Physics – Class 11 Practice Test 6

1. What is the value of universal gravitational constant?

6.67 x 10^-11 N m²/kg²

9.81 m/s²

6.022 x 10²³

1.602 x 10^-19 C

2. The radius of the moon is approximately 3.7 times smaller than the radius of the earth. Assuming that their densities are same, what is the escape velocity of the moon compared to earth?

0.7 times

0.07 times

7 times

3.7 times

3. Acceleration due to gravity increases as we go towards the centre of the earth.

False

True

4. Which of the following is the variation of acceleration due to gravity at a depth “d” below the earth’s surface? Let “R” be the radius of the earth and “M1” the mass of earth. (Assume the density of the earth to be constant)

g = [(G*M1) x density]/d

g = (G*M1)/(R - d)

g = (G x M1/R³) x (R – d)

g = (G x M1/R³) / (R – d)

5. The gravitational constant is an empirical constant.

True

False

6. What is the speed of a point of sphere in contact with the plank, if the sphere is in pure rolling motion in the given diagram? Consider the velocity of the plank to be positive.

-2v

-v

7. Assume that the earth is a perfect sphere but of non-uniform interior density. Then, acceleration due to gravity on the surface of the earth _____

will be equal at all points on the surface and directed towards the geometric centre

cannot be zero at any point

will be different at different points on the surface

will be towards the geometric centre

8. The value of universal gravitational constant changes is which of the following medium?

The gravitational constant is independent of the medium

Plasma

Air

Water

9. In the diagram given below what is the direction of friction if the body is in pure rotational motion?

Down the incline

Up the incline

Depends on angle on inclination

Zero

10. For which of the following does the graph denote the variation of force of gravity “F” along a distance “r”?

Plate

Point

Solid sphere

Spherical shell