Q. If the angle of elevation of a hill from a point on the ground is 30 degrees and the distance from the point to the base of the hill is 100 m, what is the height of the hill? (2021)
A.
50 m
B.
30 m
C.
20 m
D.
10 m
Solution
Height = distance * tan(30) = 100 * (1/√3) ≈ 57.74 m, which rounds to 50 m.
Q. If the angle of incidence is equal to the angle of refraction, what can be said about the two media?
A.
They are the same medium.
B.
They have the same refractive index.
C.
The light is traveling in a vacuum.
D.
The light is not refracted.
Solution
When the angle of incidence equals the angle of refraction, it indicates that the light is passing from one medium to another of the same optical density, hence they are the same medium.
Q. If the angle of incidence is equal to the angle of refraction, what is the medium?
A.
Vacuum
B.
Air
C.
Glass
D.
Optically denser medium
Solution
According to Snell's law, if the angle of incidence equals the angle of refraction, the light is traveling in the same medium, which can be vacuum or air.
Q. If the angle of incidence is equal to the critical angle, what is the behavior of the light ray?
A.
It is refracted at 90°.
B.
It is totally internally reflected.
C.
It is absorbed.
D.
It is transmitted.
Solution
When the angle of incidence equals the critical angle, the light ray is refracted along the boundary at 90°, marking the threshold for total internal reflection.
Q. If the angle of inclination of a plane increases, what happens to the static friction force acting on an object resting on the plane?
A.
Increases
B.
Decreases
C.
Remains constant
D.
Becomes zero
Solution
As the angle increases, the component of gravitational force parallel to the plane increases, which can lead to a decrease in static friction until it reaches its maximum value.
Q. If the angle of inclination of a plane increases, what happens to the static frictional force acting on an object resting on the plane?
A.
Increases
B.
Decreases
C.
Remains constant
D.
Becomes zero
Solution
As the angle increases, the component of gravitational force parallel to the plane increases, which can lead to a decrease in static friction until it reaches its maximum value.
Q. If the angles of a quadrilateral are in the ratio 1:2:3:4, what is the measure of the largest angle?
A.
90 degrees
B.
120 degrees
C.
150 degrees
D.
180 degrees
Solution
Let the angles be x, 2x, 3x, and 4x. The sum of angles in a quadrilateral is 360 degrees. Therefore, x + 2x + 3x + 4x = 360, which gives 10x = 360, so x = 36 degrees. The largest angle = 4x = 144 degrees.
Q. If the angles of a triangle are in the ratio 2:3:4, what is the measure of the largest angle?
A.
60 degrees
B.
80 degrees
C.
90 degrees
D.
120 degrees
Solution
Let the angles be 2x, 3x, and 4x. The sum of angles in a triangle is 180 degrees. Therefore, 2x + 3x + 4x = 180. Solving gives x = 20, so the largest angle is 4x = 80 degrees.