21). What is the angle of elevation of the Sun when the shadow of a pole is \( \Large \sqrt{3} \) times the length of the pole?
A). \( \Large 30 ^{\circ} \) |
B). \( \Large 45 ^{\circ} \) |
C). \( \Large 60 ^{\circ} \) |
D). None of these |
|
22). The shadow of a tower is 15 m, when the Sun's elevation is \( \Large 30 ^{\circ} \). What is the length of the shadow, when the Sun's elevation is \( \Large 60 ^{\circ} \)?
A). 3m |
B). 4m |
C). 5m |
D). 6m |
|
23). What is the angle of elevation of the Sun. when the shadow of a pole of height x m is \( \Large \frac{x}{\sqrt{3}} \)
A). \( \Large 30 ^{\circ} \) |
B). \( \Large 45 ^{\circ} \) |
C). \( \Large 60 ^{\circ} \) |
D). \( \Large 75 ^{\circ} \) |
|
24). A vertical stick 12 In long casts a shadow 8 m long on the ground. At the same time, a tower casts a shadow of 40m long on the ground. The height of the tower is
A). 60 m |
B). 65 m |
C). 70 m |
D). 72 m |
|
25). The tops of two poles of height 24 m and 36 m are connected by a wire. If the wire makes an angle of \( \Large 60 ^{\circ} \) with the horizontal, then the length of the wire is
A). \( \Large 8\sqrt{3} \) m |
B). 8m |
C). \( \Large 6\sqrt{3} \) m |
D). 6m |
|
26). The shadow of a tower standing on a level plane is found to be 50 m longer when the Sun's elevation is \( \Large 30 ^{\circ} \). When it is \( \Large 60 ^{\circ} \), then what is the height of the tower?
A). 25m |
B). \( \Large 25\sqrt{3} \) m |
C). \( \Large \frac{25}{\sqrt{3}} \) |
D). 30m |
|
27). The angle of elevation of the tip of a tower from a point on the ground is \( \Large 45 ^{\circ} \). Moving 21 m directly towards the base of the tower, the angle of elevation changes to \( \Large 60 ^{\circ} \). What is the height of the tower, to the nearest metre?
A). 48 m |
B). 49 m |
C). 50 m |
D). 51 m |
|
28). The angles of depression from the top of a light house of two boats are \( \Large 45 ^{\circ} \) and \( \Large 30 ^{\circ} \) towards the west. If the two boats are 5 m apart, then the height of the light house is
A). \( \Large \left(2.5\sqrt{3}-1\right) m \) |
B). \( \Large 2.5 \left(\sqrt{3}-1\right) m \) |
C). \( \Large \left(2.5\sqrt{3}+1\right) m \) |
D). \( \Large 2.5 \left(\sqrt{3}+1\right) m \) |
|
29). The angle of elevation of the top of an unfinished pillar at a point 150m from its base is \( \Large 30 ^{\circ} \). If the angle of elevation at the same point is to be \( \Large 45 ^{\circ} \), then the pillar has to be raised to a height of how many meters?
A). 59.4m |
B). 61.4m |
C). 62.4m |
D). 63.4m |
|
30). From the top of a cliff 200 m high, the angles of depression of the top and bottom of a tower are observed to be \( \Large 30 ^{\circ} \) and \( \Large 45 ^{\circ} \), respectively. What is the height of the tower?
A). 400 m |
B). \( \Large 400\sqrt{3} \) m |
C). \( \Large \frac{400}{\sqrt{3}} \) m |
D). None of these |
|