CBSE Class 10 Heights and Distances MCQs – Angles of Elevation and Depression
CBSE Class 10 Heights and Distances MCQs – Angles of Elevation and Depression
Class: 10 | Subject: Mathematics
Chapter 9: Some Applications of Trigonometry
Board: CBSE Board Examination (Based on Latest NCERT Curriculum)
1. The angle of elevation of the top of a tower from a point 50 m away is 45°. The height of the tower is:
Correct Answer: C. 50 m
Explanation: tan 45° = height/base = h/50. Since tan 45° = 1, therefore h = 50 m.
Explanation: tan 45° = height/base = h/50. Since tan 45° = 1, therefore h = 50 m.
2. If the angle of elevation of a cloud from a point is 30° and the horizontal distance is 100 m, the height of the cloud is:
Correct Answer: A. 57.7 m
Explanation: tan 30° = h/100. Since tan 30° = 1/√3, h = 100/√3 = 57.7 m.
Explanation: tan 30° = h/100. Since tan 30° = 1/√3, h = 100/√3 = 57.7 m.
3. Angle of depression is measured from:
Correct Answer: B. Horizontal line
Explanation: Angle of depression is formed between the horizontal line and the line of sight downward.
Explanation: Angle of depression is formed between the horizontal line and the line of sight downward.
4. If tan θ = 1, then θ equals:
Correct Answer: B. 45°
Explanation: tan 45° = 1. Hence θ = 45°.
Explanation: tan 45° = 1. Hence θ = 45°.
5. The angle of elevation increases when the observer moves:
Correct Answer: B. Closer to object
Explanation: As distance decreases, opposite side remains same but adjacent decreases, so tan θ increases.
Explanation: As distance decreases, opposite side remains same but adjacent decreases, so tan θ increases.
6. sin 30° equals:
Correct Answer: A. 1/2
Explanation: Standard trigonometric value of sin 30° is 1/2.
Explanation: Standard trigonometric value of sin 30° is 1/2.
7. A flagstaff 10 m high casts a shadow 10 m long. The angle of elevation of sun is:
Correct Answer: B. 45°
Explanation: tan θ = 10/10 = 1 ⇒ θ = 45°.
Explanation: tan θ = 10/10 = 1 ⇒ θ = 45°.
8. cos 60° equals:
Correct Answer: A. 1/2
Explanation: cos 60° = 1/2.
Explanation: cos 60° = 1/2.
9. If cot θ = 1, then θ is:
Correct Answer: B. 45°
Explanation: cot 45° = 1.
Explanation: cot 45° = 1.
10. sec 60° equals:
Correct Answer: B. 2
Explanation: sec 60° = 1/cos60° = 1/(1/2)=2.
Explanation: sec 60° = 1/cos60° = 1/(1/2)=2.
11. tan 60° equals:
Correct Answer: A. √3
Explanation: Standard value of tan 60° is √3.
Explanation: Standard value of tan 60° is √3.
12. Angle of depression equals angle of elevation because they are:
Correct Answer: C. Corresponding
Explanation: When two lines are parallel, angles formed are equal.
Explanation: When two lines are parallel, angles formed are equal.
13. If a building is 20 m high and angle of elevation is 30°, distance is:
Correct Answer: A. 20√3 m
Explanation: tan30° = 20/d ⇒ d = 20√3.
Explanation: tan30° = 20/d ⇒ d = 20√3.
14. cosec 30° equals:
Correct Answer: A. 2
Explanation: cosec 30° = 1/sin30° = 2.
Explanation: cosec 30° = 1/sin30° = 2.
15. If height doubles and distance same, tan θ becomes:
Correct Answer: C. Double
Explanation: tanθ = opposite/adjacent. If opposite doubles, tanθ doubles.
Explanation: tanθ = opposite/adjacent. If opposite doubles, tanθ doubles.
16. The trigonometric ratio used mostly in heights and distances is:
Correct Answer: C. tan
Explanation: tanθ relates height and base directly.
Explanation: tanθ relates height and base directly.
17. If shadow increases, angle of elevation:
Correct Answer: B. Decreases
Explanation: Greater base means smaller tan value.
Explanation: Greater base means smaller tan value.
18. cos 0° equals:
Correct Answer: B. 1
Explanation: cos0° = 1.
Explanation: cos0° = 1.
19. tan 30° equals:
Correct Answer: A. 1/√3
Explanation: Standard trigonometric value.
Explanation: Standard trigonometric value.
20. If θ increases from 30° to 60°, tan θ:
Correct Answer: C. Increases
Explanation: tan30° = 1/√3 and tan60° = √3. Hence it increases.
Explanation: tan30° = 1/√3 and tan60° = √3. Hence it increases.
