Angular MCQs with answers Page - 12

Dear candidates you will find MCQ questions of Angular here. Learn these questions and prepare yourself for coming examinations and interviews. You can check the right answer of any question by clicking on any option or by clicking view answer button.
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Q. What is a key benefit of using Angular's OnPush change detection strategy?

  • (A) Eager loading all components
  • (B) Improved performance by reducing change detection
  • (C) Adding extra watchers
  • (D) Automatically unsubscribing Observables
💬 Discuss
✅ Correct Answer: (B) Improved performance by reducing change detection
Explanation: OnPush limits change detection to only when input references change, enhancing performance.

Published by Mr. Dubey ⭐ 111.54K Points at 08-Jun-2025 11:47 am in Angular

Q. How can services be shared across all modules in Angular?

  • (A) Add them in any component
  • (B) Provide them in a child component
  • (C) Provide them in root injector using providedIn: 'root'
  • (D) Declare them in component metadata
💬 Discuss
✅ Correct Answer: (C) Provide them in root injector using providedIn: 'root'
Explanation: Services with `providedIn: 'root'` are singleton and shared across the app.

Published by Mr. Dubey ⭐ 111.54K Points at 08-Jun-2025 11:47 am in Angular

Q. What does the async pipe automatically do in templates?

  • (A) Refresh DOM manually
  • (B) Subscribe and unsubscribe from Observables
  • (C) Reload entire component
  • (D) Prevent memory leaks
💬 Discuss
✅ Correct Answer: (B) Subscribe and unsubscribe from Observables
Explanation: Async pipe manages subscription lifecycle automatically in templates.

Published by Mr. Dubey ⭐ 111.54K Points at 08-Jun-2025 11:47 am in Angular

Q. Which file contains metadata for the root Angular module?

  • (A) index.html
  • (B) main.ts
  • (C) app.module.ts
  • (D) angular.json
💬 Discuss
✅ Correct Answer: (C) app.module.ts
Explanation: app.module.ts declares and bootstraps the root module.

Published by Mr. Dubey ⭐ 111.54K Points at 08-Jun-2025 11:47 am in Angular

Q. Which method is used in Angular to clone an Observable?

  • (A) shareReplay()
  • (B) pipe()
  • (C) clone()
  • (D) repeat()
💬 Discuss
✅ Correct Answer: (A) shareReplay()
Explanation: shareReplay allows multicasting of the same Observable without multiple subscriptions.

Published by Mr. Dubey ⭐ 111.54K Points at 08-Jun-2025 11:47 am in Angular

Q. What is the use of ChangeDetectorRef in Angular?

  • (A) Creating dynamic components
  • (B) Manual triggering of change detection
  • (C) Routing between views
  • (D) Event handling
💬 Discuss
✅ Correct Answer: (B) Manual triggering of change detection
Explanation: ChangeDetectorRef provides APIs to manually trigger or detach change detection.

Published by Mr. Dubey ⭐ 111.54K Points at 08-Jun-2025 11:47 am in Angular

Q. How can you track identity of items in ngFor for performance?

  • (A) Using index
  • (B) Using key
  • (C) Using trackBy function
  • (D) Using map operator
💬 Discuss
✅ Correct Answer: (C) Using trackBy function
Explanation: trackBy improves performance by identifying items uniquely during changes.

Published by Mr. Dubey ⭐ 111.54K Points at 08-Jun-2025 11:47 am in Angular

Q. Which strategy reduces Angular bundle size?

  • (A) Using ng serve
  • (B) Importing all modules at once
  • (C) Lazy loading modules
  • (D) Using inline templates
💬 Discuss
✅ Correct Answer: (C) Lazy loading modules
Explanation: Lazy loading defers module loading, reducing initial bundle size.

Published by Mr. Dubey ⭐ 111.54K Points at 08-Jun-2025 11:47 am in Angular

Q. What happens if you forget to unsubscribe from a subscription?

  • (A) Component runs faster
  • (B) No effect
  • (C) Memory leaks may occur
  • (D) Template errors
💬 Discuss
✅ Correct Answer: (C) Memory leaks may occur
Explanation: Not unsubscribing from subscriptions can cause memory leaks.

Published by Mr. Dubey ⭐ 111.54K Points at 08-Jun-2025 11:47 am in Angular

Q. Which Angular compiler replaced ViewEngine?

  • (A) Ivy
  • (B) NGCC
  • (C) RxJS
  • (D) Zone.js
💬 Discuss
✅ Correct Answer: (A) Ivy
Explanation: Ivy is the newer rendering and compilation engine in Angular for better performance.

Published by Mr. Dubey ⭐ 111.54K Points at 08-Jun-2025 11:47 am in Angular

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