Q1.

A tower stands vertically on a bank of a river. At the point on the other bank directly opposite the tower, the angle of the top of the tower is 600  . At a point 40 meter behind this point on the same bank the angle of elevation of the top of the tower is 300 . Find the height of the tower.

  • \( {20 \sqrt{3} }\)

  •  \( {10 \sqrt{3} }\)

  • 35

  • 20

Solution:

NA

Q2.

A ladder 8 meter long reaches a point 8 meter below the top of a chimney. at the foot of the ladder the angle of elevation of the top of the chimney is 600 . Calculate the height of the chimney.

  • 10

  • 12

  • 14

  • 16

Solution:

NA

Q3.

A person sitting in an aeroplane sees two standing persons on the ground at angle of depression of 300 each, both persons are 1800 meter apart from each other and the person is just above the middle point of the line joining the two persons. Find the height of the aeroplane.

  • 330 meters

  • 281 meters

  • \( {300\sqrt{3} }\) meters

  • \( {200\sqrt{3} }\) meters

Solution:

NA

Q4.

Two ships are on the opposite side of a light house. The angle of depression of both the ships from the top of the light house 50 meter high, are 300 and 450 respectively. Find the distance between the two ships.( use \( {\sqrt{3} } = 1.732\) )

  • 435 meters

  • 234 meters

  • 98.87 meters

  • 136.6 meters

Solution:

NA

Q5.

If the angle of elevation of the cloud  from a point h meter above a lake is P and the angle of depression of its reflection in the lake is Q. Find the height of the cloud. 

  • \(h{ (cot Q + cot P)\ \over cot P - cot Q}\)

  • htanP. tanQ

  • \(h{(tanQ + tanP)\ \over tanP-tanQ}\)

  • cotP/tanQ

Solution:

NA

Q6.

A angle of elevation of a eagle from a point 100 meters above  a lake is 300. The angle of depression of its reflection in the lake is 60o. Find the height of the eagle.

  • 250

  • 200

  • 300

  • 350

Solution:

NA

Q7.

The angle of elevation of a jet plane from a point A on the ground is 60o . After a flight of 15 seconds , the angle of elevation changes to 30o . If the jet plane is flying horizontally at a  constant height of \(1500\sqrt 3\) metres, find the speed of the jet plane . 

  • 700 km/h

  • 800 km/h

  • 720 km/h

  • 850 km/h

Solution:

NA

Q8.

From a point on the horizontal plane the tangent of the angle of elevation of the top of a minar is \({5 \over 3}\). On moving 4 metres towards the foot of the minar, the tangent of the angle of elevation of the top becomes \({5 \over 2}\). Find the height of the minar .   

  • 20 metres

  • 18 metres

  • 10 metres

  • 8 metres

Solution:

NA

Q9.

The angle of elevation of an aeroplane on the ground at any instant is 45o. After 30 seconds flight , the angle of elevation changes to 30o. If the aeroplane is flying at a height of 3 kilometers, find the speed of the aeroplane . 

  • 70 m/sec

  • 75.2 m/sec

  • 72 m/sec

  • 73.2 m/sec

Solution:

NA