Practice Questions with Answers - Multiple Choice Questions

# MCQ Questions for Class 9 Science Chapter 10 Gravitation

## MCQ Questions for Class 9 Science Chapter 10 Gravitation

Multiple Choice Questions

Question 1.
The unit of G in the S.I. system is:
(a) Newton m2/kg2
(b) Newton m2 kg2
(c) Newton m kg
(d) Newton m2/kg

Question 2.
The gravitational constant is denoted by which symbol?
(a) g
(b) M
(c) G
(d) k

Question 3.
The unit of weight in the S.I. system is:
(a) kg m2
(b) Newton
(c) ms-2
(d) ms

Question 4.
When an object is released from a height, its initial velocity is:
(a) u = 100 ms-1
(b) u = 9.8 ms-1
(c) u = 0
(d) u = $$\frac{1}{2}$$

Question 5.
The relation between g and G is:
(a) $$g=\frac{\mathrm{GM}}{\mathrm{R}^{2}}$$
(b) g = GMR2
(c) $$g=\frac{M R^{2}}{G}$$
(d) $$g=\frac{\mathrm{GR}^{2}}{\mathrm{M}}$$

Answer: (a) $$g=\frac{\mathrm{GM}}{\mathrm{R}^{2}}$$

Question 6.
The mass of the earth is:
(a) 6.4 × 1024
(b) 6 × 1010 kg
(c) 6 × 1024 kg
(d) 6 × 1019 kg

Answer: (c) 6 × 1024 kg

Question 7.
The radius of the earth is:
(a) 6.4 × 10-6 m
(b) 6.4 × 106 m
(c) 4.6 × 106 m
(d) 6.4 × 104 m

Answer: (b) 6.4 × 106 m

Question 8.
By applying the universal law of gravitation, the weight of the object on the moon will be:
(a) $$\mathrm{W}_{m}=\frac{\mathrm{GR}_{m}^{2}}{\mathrm{M}_{m} \times m}$$
(b) $$\mathrm{W}_{m}=\frac{\mathrm{GM}_{m} \times \mathrm{R}_{m}^{2}}{m}$$
(c) $$\mathrm{W}_{m}=\mathrm{G} \frac{\mathrm{R}_{m}^{2} \times m}{\mathrm{M}_{m}}$$
(d) $$\mathrm{W}_{m}=\mathrm{G} \frac{\mathrm{M}_{m} \times m}{\mathrm{R}_{m}^{2}}$$

Answer: (d) $$\mathrm{W}_{m}=\mathrm{G} \frac{\mathrm{M}_{m} \times m}{\mathrm{R}_{m}^{2}}$$

Question 9.
The value of acceleration due to gravity:
(a) is the same on the equator and poles
(b) is least on poles
(c) is least on the equator
(d) increases from pole to equator

Answer: (c) is least on the equator

Question 10.
The value of quantity G in the law of gravitation:
(a) depends on the mass of earth only
(b) depends on the radius of the earth only
(c) depends on both the mass and radius of the earth
(d) is independent of the mass and radius of the earth