CBSE Board Practice

CBSE Grade X - Some Applications of Trigonometry
Question 1
1.
    • A
    • radio tower
    • stands vertically on the ground.
    • From a point on the ground,
    • the angle of elevation
    • of the top of the
    • radio tower
    • is found to be
    • 60°
    • .
    • If the distance between the point and the top of the
    • radio tower
    • is
    • 180 m
    • ,
    • find the height of the
    • radio tower
    • .
  • 90



    3
    m
  • 90



    18
    m
  • 90
    m
  • 270
    m
  • 135



    2
    m
Question 2
2.
A man in a boat rowing away from a lighthouse 90 m high, takes 0.5 min to change the angle of elevation of the top of the lighthouse from 45° to 30°. Find the speed of the boat.
  • 4.20 m/sec
  • 2.20 m/sec
  • 1.20 m/sec
  • 0.20 m/sec
  • 3.20 m/sec
Question 3
3.
The angle of elevation of the top of a building from the foot of a tower is 60°. The angle of elevation of the top of the tower from the foot of the building is 30°. If the height of the tower is 45 m, find the height of the building .
  • 148.99 m
  • 111.99 m
  • 152.99 m
  • 134.99 m
  • 131.99 m
Question 4
4.
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 10 min for the angle of depression to change from 45° to 60°, how soon after this, will the car reach the observation tower?
  • 12 min 39 sec
  • 10 min 38 sec
  • 15 min 43 sec
  • 13 min 40 sec
  • 14 min 41 sec
Question 5
5.
    • A radio tower stands vertically on the ground. From a point on the ground, the angle of elevation of the top of the radio tower is found to be 34°46'. If the distance between the observation point and the top of the radio tower is 1 m, find the distance between the observation point and the foot of the radio tower.
    • From Table of Natural Sines
      0'
      6'
      12'
      18'
      24'
      30'
      36'
      42'
      48'
      54'
      1'
      2'
      3'
      4'
      5'
      34
      0.5592
      0.5606
      0.5621
      0.5635
      0.5650
      0.5664
      0.5678
      0.5693
      0.5707
      0.5721
      2
      5
      7
      9
      12
    • From Table of Natural Cosines
      0'
      6'
      12'
      18'
      24'
      30'
      36'
      42'
      48'
      54'
      1'
      2'
      3'
      4'
      5'
      34
      0.8290
      0.8281
      0.8271
      0.8261
      0.8251
      0.8241
      0.8231
      0.8221
      0.8211
      0.8202
      2
      3
      5
      7
      8
  • 2.82 m
  • 8.82 m
  • 7.82 m
  • 0.82 m
  • 1.82 m
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)
       
      (
      5

      4
      )
    • .
    • If the height of the
    • tower
    • is
    • 100 m
    • ,
    • find the distance between
    • the observation point and the top of the
    • tower
    • .
  • 125.00 m
  • 139.00 m
  • 108.00 m
  • 107.00 m
Question 7
7.
The angles of depression of two boats from the top of a cliff 180 m high are 30° and 60° respectively. Find the distance between the boats, if the boats are on the opposite sides of the cliff .
  • 433.71 m
  • 421.71 m
  • 389.71 m
  • 400.71 m
  • 415.71 m
Question 8
8.
    • There are two temples one on each bank of a river, just opposite to each other. One of the temples is 90 m high. As observed from the top of this temple, the angles of depression of the top and foot of the other temple are 48°1' and 61°3' 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'
      48
      1.1106
      1.1145
      1.1184
      1.1224
      1.1263
      1.1303
      1.1343
      1.1383
      1.1423
      1.1463
      7
      13
      20
      27
      33
    • From Table of Natural Tangents
      0'
      6'
      12'
      18'
      24'
      30'
      36'
      42'
      48'
      54'
      1'
      2'
      3'
      4'
      5'
      61
      1.8040
      1.8115
      1.8190
      1.8265
      1.8341
      1.8418
      1.8495
      1.8572
      1.8650
      1.8728
      13
      26
      38
      51
      64
  • 39.67 m
  • 34.67 m
  • 31.67 m
  • 29.67 m
  • 37.67 m
Question 9
9.
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 45° and the angle of elevation of the top of the building is 30°. If the height of the building is 9 m, find the height of the flag staff .
  • 5.59 m
  • 7.59 m
  • 6.59 m
  • 8.59 m
  • 4.59 m
Question 10
10.
    • The upper part of a tree is broken into two parts without being detatched. It makes an angle of 51°11' with the ground. The top of the tree touches the ground at a distance of 100 m from the foot of the tree . Find the height of the tree before it was broken.
    • From Table of Natural Tangents
      0'
      6'
      12'
      18'
      24'
      30'
      36'
      42'
      48'
      54'
      1'
      2'
      3'
      4'
      5'
      51
      1.2349
      1.2393
      1.2437
      1.2484
      1.2527
      1.2572
      1.2617
      1.2662
      1.2708
      1.2753
      8
      15
      23
      30
      38
    • From Table of Natural Cosines
      0'
      6'
      12'
      18'
      24'
      30'
      36'
      42'
      48'
      54'
      1'
      2'
      3'
      4'
      5'
      51
      0.6293
      0.6280
      0.6266
      0.6252
      0.6239
      0.6225
      0.6211
      0.6198
      0.6184
      0.9170
      2
      5
      7
      9
      12
  • 279.85 m
  • 288.85 m
  • 300.85 m
  • 283.85 m
  • 271.85 m