CBSE Board Practice

CBSE Grade X - Some Applications of Trigonometry
Question 1
1.
A flag is hoisted at the top of a building . From a point on the ground, the angle of elevation of the top of the flag staff is 60° and the angle of elevation of the top of the building is 45°. If the height of the flag staff is 11 m, find the height of the building .
  • 15.03 m
  • 10.03 m
  • 20.03 m
  • 18.03 m
  • 12.03 m
Question 2
2.
    • There are two temples one on each bank of a river, just opposite to each other. One of the temples is 140 m high. As observed from the top of this temple, the angles of depression of the top and foot of the other temple are 37°38' and 49°33' respectively. Find the height of the other temple.
    • From Table of Natural Tangents
      0'
      6'
      12'
      18'
      24'
      30'
      36'
      42'
      48'
      54'
      1'
      2'
      3'
      4'
      5'
      37
      0.7536
      0.7563
      0.7590
      0.7618
      0.7646
      0.7673
      0.7701
      0.7729
      0.7757
      0.7785
      5
      9
      14
      19
      23
    • From Table of Natural Tangents
      0'
      6'
      12'
      18'
      24'
      30'
      36'
      42'
      48'
      54'
      1'
      2'
      3'
      4'
      5'
      49
      1.1504
      1.1544
      1.1585
      1.1626
      1.1667
      1.1708
      1.1750
      1.1792
      1.1833
      1.1875
      7
      14
      21
      27
      34
  • 52.97 m
  • 47.97 m
  • 50.97 m
  • 42.97 m
  • 44.97 m
Question 3
3.
There are two temples one on each bank of a river, just opposite to each other. One of the temples is 160 m high. As observed from the top of this temple, the angles of depression of the top and foot of the other temple are 30° and 60° respectively. Find the height of the other temple.
  • 110.66 m
  • 128.66 m
  • 99.66 m
  • 106.66 m
  • 90.66 m
Question 4
4.
    • A tower stands vertically on the ground. From a point on the ground, the angle of elevation of the top of the tower is found to be 50°19'. If the height of the tower is 18 m, find the distance between the observation point and the top of the tower.
    • From Table of Natural Tangents
      0'
      6'
      12'
      18'
      24'
      30'
      36'
      42'
      48'
      54'
      1'
      2'
      3'
      4'
      5'
      50
      1.1918
      1.1960
      1.2002
      1.2045
      1.2088
      1.2131
      1.2174
      1.2218
      1.2261
      1.2305
      7
      14
      22
      29
      36
    • From Table of Natural Sines
      0'
      6'
      12'
      18'
      24'
      30'
      36'
      42'
      48'
      54'
      1'
      2'
      3'
      4'
      5'
      50
      0.7660
      0.7672
      0.7683
      0.7694
      0.7705
      0.7716
      0.7727
      0.7738
      0.7749
      0.7760
      2
      4
      6
      7
      9
  • 26.39 m
  • 28.39 m
  • 23.39 m
  • 18.39 m
  • 20.39 m
Question 5
5.
If P is the point of observation and the observed object is at point O, which of the following angles represent the angle of elevation ?
  • ∠d
  • ∠e
  • ∠g
  • ∠f
Question 6
6.
    • A
    • tower
    • stands vertically on the ground.
    • From a point on the ground,
    • the angle of elevation
    • of the top of the
    • tower
    • is found to be
    • cosec
      (-1)
       
      (
      7

      6
      )
    • .
    • If the height of the
    • tower
    • is
    • 20 m
    • ,
    • find the distance between
    • the observation point and the top of the
    • tower
    • .
  • 23.33 m
  • 28.33 m
  • 18.33 m
  • 26.33 m
  • 20.33 m
Question 7
7.
A man on the top of a vertical observation tower observes a car moving at a uniform speed coming directly towards him. If it takes 14 min for the angle of depression to change from 45° to 60°, how soon after this, will the car reach the observation tower?
  • 19 min 7 sec
  • 18 min 11 sec
  • 21 min 14 sec
  • 17 min 10 sec
  • 20 min 13 sec
Question 8
8.
The shadow of a vertical tower BA on a level ground is increased by 35 m, when the altitude of the sun changes from 45° to 30°. Find the height of the tower .
  • 52.82 m
  • 50.82 m
  • 42.82 m
  • 47.82 m
  • 44.82 m
Question 9
9.
    • Two poles of equal height are standing opposite to each other on either side of a road which is 30 m wide. From a point between them on the road, the angles of elevation of the top of the poles are 46°11' and 50°26' respectively. Find the height of each pole and the distances of the point from the two poles .
    • From Table of Natural Tangents
      0'
      6'
      12'
      18'
      24'
      30'
      36'
      42'
      48'
      54'
      1'
      2'
      3'
      4'
      5'
      46
      1.0355
      1.0392
      1.0428
      1.0464
      1.0501
      1.0538
      1.0575
      1.0612
      1.0649
      1.0686
      6
      12
      18
      25
      31
    • From Table of Natural Tangents
      0'
      6'
      12'
      18'
      24'
      30'
      36'
      42'
      48'
      54'
      1'
      2'
      3'
      4'
      5'
      50
      1.1918
      1.1960
      1.2002
      1.2045
      1.2088
      1.2131
      1.2174
      1.2218
      1.2261
      1.2305
      7
      14
      22
      29
      36
      • height =
      • 14.8 m
      • , distances away =
      • 11.88 m
      • ,
      • 14.12 m
      • height =
      • 16.8 m
      • , distances away =
      • 13.88 m
      • ,
      • 16.12 m
      • height =
      • 15.8 m
      • , distances away =
      • 12.88 m
      • ,
      • 15.12 m
      • height =
      • 17.8 m
      • , distances away =
      • 14.88 m
      • ,
      • 17.12 m
      • height =
      • 18.8 m
      • , distances away =
      • 15.88 m
      • ,
      • 18.12 m
Question 10
10.
The angle of elevation of the top of a building from the foot of a tower is 30°. The angle of elevation of the top of the tower from the foot of the building is 45°. If the height of the tower is 80 m, find the height of the building .
  • 41.19 m
  • 46.19 m
  • 43.19 m
  • 51.19 m
  • 49.19 m