Draw on your desktop screen

How to write on any screen or browser

First Install Gnome Extension

sudo apt install gnome-tweaks

sudo apt install gnome-shell-extensions

Ubuntu: With the screen drawing extension installed and enabled in GNOME Shell you can hit the super + alt + D key combo to bring up the drawing features.

Shortcut keys

Plan and Development process involved in animation

How To Make Animation Videos For YouTube  

Prerequisites:

Decide which software to use for Animation:

Use Shotcut, 2D Pencil, GIMP, Inkscape, Audacity on UBUNTU 20.04

Know your constraints:

Budget

Timeline

Target Audience

Video Duration

Video size

Should it include a subtitle

Does it support multiple languages

Know in advance about color, specific styles, and characters that should be used.

Plan:

Create a workflow & a project plan

Know your content, story, and characters.

Plan background, scenes, and kind of music, audio for all the scenes before it is implemented using the software.

Plan your Timings for each scene.

Process:

The development process of 2D animation:

→ Script 

→ Voice Over Recording 

→ Style Frame 

→ Storyboard 

→ Animatic/Boardomatic

→ Design Assets

→ Animation 

→ Music and Sound Design

Should have a powerful message.

Google App Script (Macro on google spreadsheet)

 Google App Script (Macro on google spreadsheet)

I will teach you how to write a script on a spreadsheet.

For free demo class contact: nagashwinicomputers@gmail.com

Check these extra menus on a spreadsheet. This is done using coding.

Students also can learn this (Grade 8 and above).

Wordpress Interview Questions

 Wordpress Questions and Answers

1.Static v/s Dynamic Website Design

There are basically two main types of website - static and dynamic. A static site is one that is usually written in plain HTML and what is in the code of the page is what is displayed to the user. A dynamic site is one that is written using a server-side scripting language such as PHP

2. What is content management system (CMS)

A content management system (CMS) is a software application or set of related programs that are used to create and manage digital content. CMSes are typically used for enterprise content management (ECM) and web content management (WCM).

3. What is an API

API (Application Programming Interface) is a set of functions and procedures that allow the creation of applications which access the features or data of an operating system, application, or other service.

4. Posts vs. Pages (Key Differences)

Posts are timely vs. Pages are timeless.

Posts can be categorized vs. Pages are hierarchical.

5. What is a WordPress Plugin

A plugin is a piece of software containing a group of functions that can be added to a WordPress website. They can extend functionality or add new features to your WordPress websites. WordPress plugins are written in the PHP programming language and integrate seamlessly with WordPress.

6. What is a WordPress Theme? What does they provide.

A WordPress theme provides all of the front end styling of your WordPress site.

Most WordPress themes provide:

the overall design or style of your site

font styling

colors

widget locations

page layouts (or templates)

styles for blog posts and blog archives

additional stylistic details

7. Difference between template and theme 

A theme is a complete package of files to define the look & feel (& some functionality). A template is just one of the files that makes up a theme.

Custom Fields and Meta Boxes are essentially the same, they allow you to store extra data/information in the postmeta table in the database. The data is stored in a key/value pair. And are attached to the post or page by id. Using the add_post_meta function.

add_post_meta($ID, 'name_of_data_to_store', 'value_of_that_data');

The key difference is that Custom Fields are native to wordpress so each post/page has them built-in.

8. What is SEO?

Search engine optimization is a methodology of strategies, techniques and tactics used to increase the amount of visitors to a website by obtaining a high-ranking placement in the search results page of a search engine (SERP) -- including Google, Bing, Yahoo and other search engines.

9. Categories vs. Tags

Categories allowed for a broad grouping of post topics, but when you wanted to describe a post in more specific terms, more categories were required. That led to very long category lists inside the blog and very long lists in Categories Widgets.

Tags are similar to categories, but they are generally used to describe your post in more detail.

10. What is the difference between a framework and a library

A library is usually a piece of reusable code, you use for specific functionality. You access the library through an API for executing a specific function. For eg You use JDBC as the API to look up the library that deals with database connection, retrieval of data. 

When you are speaking of Frameworks, it is more of a collection of libraries that can be accessed through an API.  It also dictates the architecture your application works with,where you have to factor the code as per the framework and design.

11.What Actually Are Custom Post Types?

Custom Post Types are a new set of administrative options appearing along with the default post types such as Posts, Pages, Attachments etc. A Custom Post Type can store any type of information. It has a dedicated editor, media uploader and uses the existing WordPress table structure for ease in data management. The main advantage of creating custom post types using the WordPress API is that it equips itself well with existing themes and templates.

Custom Post Types help us to keep different types of posts in different buckets. It separates our regular posts from others.

12.What is the difference between email client and webmail?

Email clients

An email client is an application that runs on your own personal computer and it uses client-server architecture. This means that your email is sent from many clients to a central server, which then sends the message to the right email addresses. If you use Outlook (part of the Microsoft Office package) or Thunderbird (comes with the Firefox browser), you’re using email clients.

The good thing about email clients is that the emails are stored on your PC and you can access them much faster than when using webmail, and the fact that you don’t need to have an internet connection if you want to read emails you received can sometimes be a huge benefit.

 Webmail 

Webmail are web-based email accounts. Emails are operated from a website, and webmail allows users to access their email accounts as long as they have an internet connection. The biggest names in webmail services are Gmail, Hotmail and Yahoo mail, so if you use any of these, you’re using webmail.

One could say that in the world of email, there are two types of email: email clients and webmail. Whether you choose to use email clients or to use webmail, just have in mind that both methods are made for reading and sending emails, the difference is just in the way of accessing them.

13. What is difference between session and cookie in php?

A cookie is a piece of data stored on the client side. Data stored in session is stored on the server side, and the various sessions are identified by cookies. A cookie is often used to identify a user. A cookie is a small file that the server embeds on the user's computer.

14. PHP Code Example to Query a WordPress Post

Query the post with post id 26 and Show the title and the content.

<?php

$post_id = 26;

$queried_post = get_post($post_id);

$title = $queried_post->post_title;

echo $title;

echo $queried_post->post_content;

?>

15. How do I make custom query with WordPress to query a db?

 <?php $wpdb->query('select * from my_plugin_table where foo = "bar"'); ?>

16. For what purpose the famous buddypress and whocommerce plugin used for? Have you used this plugin before to build the apps.

To build social networking and ecommerce site respectively. Yes

17. Differences between SOAP and REST web services.

SOAP is a protocol. REST is an architectural style.

SOAP stands for Simple Object Access Protocol. REST stands for REpresentational State Transfer.

SOAP can't use REST because it is a protocol. REST can use SOAP web services because it is a concept and can use any protocol like HTTP, SOAP.

SOAP uses services interfaces to expose the business logic. REST uses URI to expose business logic.

In Java JAX-WS is the java API for SOAP web services. In Java JAX-RS is the java API for RESTful web services.

SOAP defines standards to be strictly followed. REST does not define too much standards like SOAP.

SOAP requires more bandwidth and resource than REST. REST requires less bandwidth and resource than SOAP.

SOAP defines its own security. RESTful web services inherits security measures from the underlying transport.

SOAP permits XML data format only. REST permits different data format such as Plain text, HTML, XML, JSON etc.

SOAP is less preferred than REST. REST more preferred than SOAP.

18. When is it best to use REST and Best to use SOAP?

Why Rest? 

Since REST uses standard HTTP it is much simpler in just about ever way. 

REST permits many different data formats where as SOAP only permits XML. 

REST allows better support for browser clients due to it’s support for JSON. 

REST has better performance and scalability. REST reads can be cached, SOAP based reads cannot be cached. 

If security is not a major concern and we have limited resources. Or we want to create an API that will be easily used by other developers publicly then we should go with REST web services. 

Why SOAP? 

WS-Security: While SOAP supports SSL (just like REST) it also supports WS-Security which adds some enterprise security features. 

WS-AtomicTransaction: Need ACID Transactions over a service, you’re going to need SOAP. 

WS-ReliableMessaging: Rest doesn’t have a standard messaging system and expects clients to deal with communication failures by retrying. 

SOAP is highly secure as it defines its own security.

If the security is a major concern and the resources are not limited then we should use SOAP web services. Like if we are creating a web service for banking related work then we should go with SOAP as here high security is needed.

18. What is XML RPC?

Both utilize XML for web service method request/response encapsulation. However, XML-RPC could be described as a subset of SOAP functionality. For protocol, XML-RPC can only make requests using an HTTP/S connection; meanwhile, SOAP commonly uses HTTP/S but it can be run over a variety of other protocols.

19. Difference between Native/Hybrid and HTML5 mobile web app

HTML5:

An HTML5 app is essentially a website with JavaScript code written to allow the app to perform dynamically, as opposed to a static website that you need to "refresh" to see the changes. It works interactively to make it feel like an "app", but it is running in a web browser, and is essentially a website, which (since it looks like your focus is mobile) will support multiple viewports or screen sizes so that it works well on mobile. Because it is running in a browser, it is confined to what is known is the browser sandbox, which is a limitation on what the app is capable of doing with the system hardware. It can only support features which are permissible inside the sandbox. This is done for security reasons.

Native:

A native app is an app written to a specific platform like iOS or Android, where the app is written in the language used for development on that platform (Objective-C and Java in this case). The portability of the code to other platforms depends on how it was written (if portability was in the developer's mind), but will always require some level of rewriting to use on another platform. When you write native, you get access to all the hardware features exposed by the native code APIs, which is typically most of the functionality of the device, definitely more than a web app. Apple push notifications is one example from your list that is an iOS specific feature which is not supported by a web app. It is "Native" because the code you write is essentially written for that platform, it is built for the native architecture of that device (implicitly implying that cross-platform support might be an area of concern, and it is).

Hybrid:

A hybrid app is a web app that is deployed to a native platform like iPhone inside a native harness. This harness is usually little more than a browser view (to display the HTML5 content) and some other hooks to allow your web app to potentially access some more hardware features that are not available inside the browser sandbox. It improves code portability because if you want to port your app to another platform, you only need a native harness on that other platform to run it, the HTML5 content of the app is directly portable. These harnesses can be hand written, but can also be generated automatically by tools in the marketplace like the much lauded PhoneGap. These tools try and make a single point of contact for the developer, who can then turn around and push their app out to multiple platforms quickly by generating the harness and packages required to do so automatically. This sounds powerful, and it is, but clearly the PhoneGap people have a ton of configurations and hardware to support, and thus, the solutions do not always work the same across all devices, and in practice, testing and hacking of special cases will be required by the developer to get proper support if the app is anything more than a website in a browser control.

20. What is a feed URL?

RSS Feeds are used by feed readers like Feedly, iTunes, and other services to check websites for new content. When you publish content on your site, your RSS feed automatically updates, formatting the new content as a .xml file so it can be read by external services and RSS readers.

UX/UI Design Interview Questions

 UI Questions and Answers

1.What is Mobile First Design

Mobile first is an approach to responsive design: design for smaller screens first, then add more features and content for bigger and bigger screens. This design approach is also known as "progressive enhancement."

2. What is Adaptive web design

Adaptive web design is different from responsive design in that there isn't one layout that always changes. Instead, there are several distinct layouts for multiple screen sizes. ... For example, there could be a specific layout for mobile phones, tablets, and desktop computers – each of which are made in advance.

3. How do you make decision as how to choose which layout to design a website among fixed, responsive or adaptive?

When it comes down to it, the key is to consider your audience first and foremost no matter what design technique you adopt. Once you know exactly who they are and what devices they tend to access the site on, then it’s easier to design with them in mind when it comes to layout, content and so on.

4. What is the advantage of using minimized version of jQuery?

Efficiency of web page increases when minimized version of jQuery is used.min.js file will be more than 50% less than the normal js file. Reduction in the file size makes the web page faster.

5. What are the basic selectors in jQuery?

Following are the basic selectors in jQuery:

Name: Selects all elements which match with the given element Name.

#ID: Selects a single element which matches with the given ID

.Class: Selects all elements which match with the given Class.

Universal (*): Selects all elements available in a DOM.

Attribute Selector: Select elements based on its attribute value.

6. What is CDN?

CDN is abbreviated as Content Distribution network and it is said to be a group of companies in different location with network containing copies of data files to maximize bandwidth in accessing the data.

7. What are the two types of CDNs?

There are two types of CDNs:

Microsoft – Load jQuery from Ajax CDN

Google – Load jQuery from Google libraries API

8. What does dollar sign ($) means in jQuery?

Dollar Sign is nothing but it's an alias for JQuery. Take a look at below jQuery code. 

$(document).ready(function(){

});

Over here $ sign can be replaced with "jQuery" keyword. 

jQuery(document).ready(function(){

});

9. How do you implement animation functionality?

The .animate() method allows us to create animation effects on any numeric CSS property. This method changes an element from one state to another with CSS styles. The CSS property value is changed gradually, to create an animated effect.

Syntax is:

(selector).animate({styles},speed,easing,callback)

    styles: Specifies one or more CSS properties/values to animate.

    duration: Optional. Specifies the speed of the animation.

    easing: Optional. Specifies the speed of the element in different points of the animation. Default value is "swing".

    callback: Optional. A function to be executed after the animation completes.

Simple use of animate function is,

$("btnClick").click(function(){

  $("#dvBox").animate({height:"100px"});

});

10. In what situation you would use multiple version of jQuery and how would you include them?

Well, it is quite possible that the jQuery plugins which are used are dependent on older version but for your own jQuery code, you would like to use newer version. So because of this dependency, multiple version of jQuery may require sometimes on single page.

Below code shows how to include multiple version of jQuery. 

<script type='text/javascript' src='js/jquery_1.9.1.min.js'></script>

<script type='text/javascript'>

 var $jq = jQuery.noConflict();

</script

By this way, for your own jQuery code use "$jq", instead of "$" as "$jq" refers to jQuery 1.9.1, where "$" refers to 1.7.2.

 

11.What is chaining in jQuery?

​$(document).ready(function(){

    $('#dvContent').addClass('dummy').css('color', 'red').fadeIn('slow');     

});​

12. What is each() function in jQuery? How do you use it?

each() function allows you to iterate over a set of elements. You can pass a function to each() method, which will be executed for each element from the jQuery object, on which it has been called.

$('[name=NameOfSelectedTag] :selected').each(function(selected){

        alert($(selected).text());

});

13. Difference between $(this) and this keyword in jQuery?

$(this) returns a jQuery object, on which you can call several jQuery methods e.g. text() to retrieve text, val() to retrieve value etc, while this represent current element, and it's one of the JavaScript keyword to denote current DOM element in a context. You can not call jQuery method on this, until it's wrapped using $() function i.e. $(this).

14. What is Anchor Pseudoclasses?

a:link {color:#FF0000;} /* unvisited link */

a:visited {color:#00FF00;} /* visited link */

a:hover {color:#FF00FF;} /* mouse over link */

a:active {color:#0000FF;} /* selected link */

Note: a:hover MUST come after a:link and a:visited in the CSS definition in order to be effective!!

Note: a:active MUST come after a:hover in the CSS definition in order to be effective!!

Note: Pseudoclassnames are not casesensitive.

15. How do I hide a field?

If the fields have unique IDs or Classes you can add the follwoing css:

.yourClass {

display:none;

}

#yourID {

display:none;

}

16. How do you retrieve attribute of an HTML tag using jQuery e.g. href of links? 

$("a").each(function(){

   alert($(this).attr('href'));

});

17.What is CSS3 boxshadow Property?

boxshadow: hshadow vshadow blur spread color inset;

18. What is Twitter Bootstrap Pagination? 

Pagination is the process of organizing content by dividing it into separate pages.

19. What are Bootstrap Badges?

Badges are small and simple components for displaying an indicator or to count some sort of number. This is very useful for mail count and notification etc.

20. What is a Bootstrap Breadcrumb?

A breadcrumb is a navigation scheme that indicates the user's location in a website or web application. The following example shows how to create breadcrumbs.

21. Give the syntax of buttons in Bootstrap

Syntax of Button

<button type="button" class="btn btn-size"> 

<span class="glyphicon glyphicon-name"></span></button> 

Default

Info

Primary

Danger

success

warning

Default Button Syntax

<button type=”button” class=”btn btn-default btn-size”> 

Default 

</button> 

22. What are media queries

"Responsive Design" is the strategy of making a site that "responds" to the browser and device that it is being shown on... by looking awesome no matter what. 

Media queries are the most powerful tool for doing this. Let's take our layout that uses percent widths and have it display in one column when the browser is too small to fit the menu in the sidebar: 

@media screen and (min-width:600px) {

  nav {

    float: left;

    width: 25%;

  }

  section {

    margin-left: 25%;

  }

}

@media screen and (max-width:599px) {

  nav li {

    display: inline;

  }

}

23. What is panel in Bootstrap?

A panel in bootstrap is a bordered box with some padding around its content. To create a basic panel, we use .panel class to the <div> element, and content inside the panel has a .panel-body class.

24. What is Bootstrap Container in Bootstrap?

Bootstrap container is a class which is useful and creating a centred area in the page for display.

25. What are CSS Preprocessors

Both Sass and Less are CSS preprocessors, which allow writing clean CSS in a programming construct instead of static rules.

A preprocessor is a program that takes in one “type of data and converts it to another type of data

LESS and Sass share a lot of similarities in syntax, including the following:

Mixins – Classes for classes.

Parametric mixins – Classes to which you can pass parameters, like functions.

Nested Rules – Classes within classes, which cut down on repetitive code.

Operations – Math within CSS.

Color functions – Edit your colors.

Namespaces – Groups of styles that can be called by references.

Scope – Make local changes to styles.

JavaScript evaluation – JavaScript expressions evaluated in CSS.

 

SEO Optimisation for blogger

Generate Sitemap both HTML and XML

then under blogger settings import the sitemap.xml

Create sitemap.html page in blogger.

submit the sitemap.xml to the google search console.

Blockchain MCQ (quiz)

 Blockchain

1. The blockchain is a ---------------- of immutable records.

a. Decentralized distributed database

b. Centralized database

c. Relational Database

d. Spreadsheet

a

2. The technology was discovered with the invention of Bitcoins which is the ---------------

a. the first cryptocurrency

b. Second cryptocurrency

c. Third cryptocurrency

d. Fourth cryptocurrency

a

3. Concept of Ethereum

a. Bigdata

b. Machine Learning

c. Programming Language

d. Smart Contract

d

4. Concept of Bitcoin

a. Bigdata

b. Machine Learning

c. Programming Language

d. Cryptocurrency

d

5. Founder of Bitcoin

a. Satoshi Nakamoto

b. Santoshi Charli

c. Nakamoto Basco

d. Alexander

a

6. Founder of Ethereum

a. Alexander

b.Vitalik Buterin

c. Satoshi Nakamoto

d. Lara

b

7. Release Method of Bitcoin/Ethereum

a. Genesis Block Mined/Presale

b. Presale/Tokensale

c. Smartcontract/Cryptocurrency

d. Tokensale/Mining

a

8. Algorithm used Bitcoin/Ethereum

a. SHA256/Ethash

b. MD5/Bcrypt

c. Ethash/SHA256

d. MD5/SHA256

a

9.What is the principle on which blockchain technology is based on?

a. Distributed

b. Organizing

c. Planing

d. Coordinating

a

10. Distributed Network Means

a. There is no one central point of failure and also no single person can behave recklessly to damage the entire chain of network.

b. Allocation of resources, both hardware and software, to each individual workstation, or office location

a

11. Types of Blockchain

a. Public/Private/Consortium

b. Distributed/Decentralized/Trustless

a

12. Blocks in blockchain consist of ---------------

a. List of transaction records

b. Header

c. Payload

d. Message

a

13. Is it possible to modify the data once it is written in a block?

a. Yes

b. No

b

14. Blockchain is ----

a. online ledger

b. offline ledger

a

15. Block Identifiers in Blockchain can be identified by

a. the block header hash and the block height.

b. Payload and message

a

16. Each leaf node is a hash of a ----- of data, and each non-leaf node is a hash of its --- nodes.

a. Block / Child

b. Parent / Child

a

17. Datastructure used in blockchain

a. Merkle Tree

b. Hierarchial Tree

a

18. The amount of data cannot be larger than the ----

a. Blockchains address size

b. Block size

a

19. What is Hash?

a. A hash is a generated string, that is computed using our data is input.

b. Password

a

20. Traditional Database pros

a. Single point of failure

b. Controlled by one central authority

c.  Missing Transparency

d. Cheap storage for large amounts of data

d

21. Where Blockchain really shines

a. Transparency

b. Data consistency

a

22. Common type of ledgers that can be considered by users in Blockchain

a. Decentralized Ledgers

b. Distributed Ledgers

c. Centralized Ledger

a,b,c

23. Decentralization 

a. rely on a peer-to-peer network built on a community of users.

b. is an interconnected group of storage facilities and transportation systems that receive inventories of goods and then deliver them to customers.

A

24. Bitcoin is based on ________ blockchain?

a. Public

b. Private

c. Public Permissioned

d. Permissioned

a

25. ockchain can be stored as which of the following?

a. A flat file

b. A Database

c. Both of the above [Ans]

d.None of the above

26. In blockchain, blocks are linked ________?

a. Backward to the previous block [Ans]

b. Forward to next block

c. Not linked with each other

27. The primary benefit of immutability is…

a. Scalability

b. Improved Security

c. Tamper Proof

d. Increased Efficiency[Ans]

28. Hash identifying each block in the Blockchain is generated using which of the following cryptographic algorithm?

SHA128

SHA256 [Ans]

29. A block in the blockchain can never have more than one parent block?

True [Ans]

False

30. Blockchain forks can result in which of the following?

Multiple parent blocks

Multiple children blocks [Ans]

31. Which of the following is asymmetric encryption Algorithm?

Blowfish

Twofish

RSA [Ans]

Tripple DEA

32. Which is not a consenses algorithm

a. PBFT (Practical Byzantine Fault Tolerance)

b. Proof-of-work

c. Proof-of-stake

d. Tokenization

33. What is the value token for Ethereum?

a. ETH

b. ETC

a

34. What is the difference between Wei and Ether?

a. Wei is a denomination. 1 ETH = 10¹⁸ Wei

b.  Wei is a denomination. 10 ETH = 10¹⁸ Wei

a

35. What is the average block time in Ethereum?

a. ~14 seconds

b. ~120 seconds

a

36.Does Ethereum support scripting? If so, what types of scripting?

a.Yes

b. No

a

37. What is the average block size in Ethereum?

a. Around 2KB, although it depends.

b. Around 2MB, although it depends.

A

38. Below are ways of getting Ethers? Find odd one out.

1. Become a miner

2. Trade other currencies

3. Foreign Exchange

4. Receive Ethers from others

39. Storage resides in ------------

a. Contract-state variables.

b. Functions

a

40. Memory, on the other hand, holds ------ items and ----- between function calls.

a. Permanent/ Cannot be Erased

b. Temporary/ can be Erased

b

41. ----- is a token standard that describes different functions and events that must be implemented in an Ethereum token contract.

a.ERC21

b.ERC20

b

42. The distinctive feature is that all ERC721 tokens are ------. An interface has to allow these tokens to be managed/owned/traded.

a. Unique

b. Immutable

a

44. Where do Ethers come from?

a. 60 million were first created in a presale in 2014. Also, ethers are created when a block is mined.

b. None of the above

a

45. ------ is essentially a computer, connected to the network, which processes transactions.

a. A Node

b. A Block

a

46.How many Ethereum networks are you familiar with?

a. 3

b. 10

a

47. What are some ways to interact with a Ethereum network?

a. Wallet or Dapp

b. Software or Webapp

48. Can you “hide” a transaction on a Ethereum network?

a.No

b.Yes

a

49.  Where are transactions recorded?

a. Public Ledger

b. Notebook

a

50. What are the ids of Ethereum networks?

A: Live (id=1), Ropsten (id=3), Rinkeby (id=4), Private (assigned by the developer)

B: None of the Above

A

51. So I can mine some Ethers in Rinkeby and transfer them to Live network, right?

a. No

b. Yes

a

52. Why would you have a private network?

a. Because of data privacy, distributed database, permissions control and testing.

b. none of the above

a

53. How can you easily see details about transactions and blocks?

a. Etherscan.io

b. Ethereum.org

a

54. Etherscan is a --------------

a. Blockchain explorer

b. File explorer

a

55. The process of validating transactions (creating blocks) following a specific protocol (like Ethereum).

a. Consensus in blockchain

b. Transaction in blockchain

56. What are the two commonly used consensus models in blockchain?

a. Proof of work and proof of stake.

b. None of the above

a

57. It is essentially a puzzle which miners have to solve in order to generate proof of work and validate a transaction. It is computationally intensive.

a. Proof of Work

b. Proof of Stake

a

58. The creator of the block is chosen randomly by means of wealth and age. It is not computationally intensive.

a. Proof of Work

b. Proof of Stake

b

59.How can you mine Ethers?

a. Wallet

b. Currency

a

60. What is used to sign transactions?

a. Private Key

b. Public Key

a

61. Can you recover your Ethereum account after losing your private key?

a. Yes

b. No

a

62. How Can you recover your Ethereum account after losing your private key?

a. You can use your 12 word mnemonic

b. You can use your 18 word mnemonic

a

63. What are some ways to connect to a node?

a. IPC-RPC, JSON-RPC and WS-RPC

b. None of the above

a

64. So what is Geth?

a. Ethereum Cli client

b. Ethereum Network

a

65. You can connet to a geth client over the network using ------

a. JSON-RPC and WS-RPC

b. IPC-RPC and WS-RPC

a

66. Which RPC APIs are enabled by default?

a. eth, web3 and net.

b. None of the above

a

67. How would you enable admin api for JSON RPC?

a. By using the option — rpcapi

b. By using the option — rpc

68. What does — testnet do?

a. It connects the client to Ropsten network.

b. It connects the client to Tes network.

A

69. How would you load custom javascript files into your geth console?

a. By passing — preload and the path of the file.

b. By passing — load and the path of the file.

A

70. Where are geth client accounts stored?

a. In the keystore directory.

b. In the datastore directory.

A

71. ---- is the account which receives the mining awards, which is account with index 0.

a.ethercoinbase

b.etherbase

b

72. ----- refers to the amount of Ether you're willing to pay for every unit of gas, and is usually measured in “Gwei”.

a. Gas Price

b. Gas value

a

73. Example of a Smart Contract use case?

a. Seller and Buyer Scenario

b. Create dynamic content on fly

a

74.--------- is a tool which helps you to easily interact with the Ethereum networks in your browser

a. Metamask

b. Ethereum

a

75. What node does Metamask use?

a. infura.io

b. geth cli

a

76. What does Metamask NOT support?

a. Mining and contract deployment.

b. Interact with Dapps and Smart Contracts

a

77. Is execution of contracts free?

a. Yes

b. No

b

78. Is accessing a Smart Contract state free?

a. Yes

b. No

a

79. Is Querying state is a transaction.

a. No

b. Yes

a

80. Who executes the contracts?

a. Miner

b. Developer

a

81. How is transaction fee calculated?

a. Gas used * gas price 

b. Ether value * gas price

a

82. Who pays for Smart Contracts invocation?

a.The user who invokes the contract.

b. Miner

a

83. What do nodes run Smart Contracts code on? 

a. EVM

b. JVM

a

84. What does the EVM need in order to run a Smart Contract?

a. Contract’s bytecode

b. Solidity code

a

85. What are the segments of EVM on a higher level?

a. Memory area, Stacks and Execution engine

b. None of the above

a

86.An online tool for developing, testing and deloying contracts.

a. Remix

b. Infura

a

87. You can connect to a public node using ----

a. Metamask

b. Geth

c. Javascript

a

88. You can connect to local node using -----

a. Metamask

b. Geth

c. Javascript

b

89.You can connect to simulated memory node in the --------------------.

a. Metamask

b. Geth

c. Javascript

c

90. -----------is an app usually consists of a client which communicates to some centralized resources (owned by an organization).

a. DAPP

b. Web APP

a

91.Is the front end of a DApp restricted to any technology/framework?

A: No. You can use anything you want, like HTML, CSS, JS, Java, Python, the list goes on.

b. Yes. Solidity

a

92. What does the front end use in order to connect to the backend (Smart Contracts)?

a. Web3 API libraries.

b. Solidity

a

93. What do you need in order to interact with a contract from a DApp?

a. The contract’s ABI and bytecode.

b. Web3 API libraries

a

94. --- is a description of the public interface of a contract, which is used by DApps for invoking the contract.

a. ABI

b. Bytecode

a

95. The EVM on each node requires --------- in order to execute the contract code.

a. Bytecode

b. ABI

a

96. Why would you use BigNumber library?

a. Because Javascript does not handle big numbers correctly.

b. None of the above

a

97.How to list accounts in web3 1.x?

a. web3.eth.getAccounts

b. web3.getAccounts

a

98. ----- sends a transaction and costs money while.----- queries the state of the contract.

a. Send/Call

b. Sell/Buy

a

99. Is sending one ether like this “.send({ value: 1 })” okay?

a. No

b. Yes

a

100. util method web3.utils.toWei(1, ‘ether’) is used to send 1 ether then I have to mutiply the value by --------

a. 10^18

b. 10^16

a

101.The only function of web3.eth.sendTransaction() is to send ethers to a specific address, is that correct?

a. No

b. Yes

a

102. Do you know any solutions for scalability in Ethereum?

a. 2-layer protocols. Possible solutions are state channels and plasma.

b. None of the above

a

103. Is Solidity statically or dynamically typed?

a. It is statically typed

b. It is dynamically typed

104. What is the equivalent to the Java “Class” in Solidity?

a. Contract

b. Pragma

a

105. An instance of a contract is the deployed contract on the blockchain.

a. Instance

b. Method

a

106. Solidity supports multiple inheritance but doesn’t support --------

a. Overloading

b. Overriding

a

107. What is the very first thing you must specify in a Solidity file?

a. Version

b. Class

a

108. Contract consists mainly of storage variables, functions and ------.

a. Events

b. Methods

a

109. There is a constructor, fallback function, constant functions and functions that modify the -------

a. Contract state

b. Blockchain state

a

110. Is it perfectly fine to put multiple contract definitions into a single Solidity file?

a. yes

b. No

a

111. A contract can invoke, create and inherit from another contract(s).

a. ways in which two contracts can interact

b. ways in which contracts can invoked

a

112. What happens when you try to deploy a file with multiple contracts?

a.The compiler only deploys the last contract in that file and all other contracts are ignored.

b. The compiler only deploys the last contract in that file and all other contracts are not ignored.

A

113.What if I have a huge project, do I need to keep all my related contracts into a single file?

A. You can use import statement to import a file

B. You can use require statement to import a file

A

114. EVM is divided into Storage, Memory and ------

a. CallData

b.sendData

a

115. ----- is a key-value datastore (256 bit key & value). The read and write are more costly in terms of gas used per execution.

A. Storage

B. Memory

A

116. ------ is a temporary storage. The data is lost once the execution terminates. You can allocate complex datatypes like arrays and structs.

a. Memory

b. Storage

a

117. -------- can be thought of as the callstack. It is temporary, non-modifiable, and it stores EVM execution data.

a. callData

b. sendData

a