The gravitational potential strictly at the center of a solid, uniform Earth of mass M and radius R is: MCQ with Answer and Explanation

The gravitational potential strictly at the center of a solid, uniform Earth of mass M and radius R is:
A. -GM / 2R
B. -GM / R
C. -3GM / 2R
D. Zero
Answer: Option C
Solution (By JKSSB Mock Tests)
The gravitational potential V inside a uniform solid sphere at a distance r from the center is V = -GM * (3R^2 - r^2) / (2R^3). At the exact center of the Earth, r = 0. Substituting r = 0 gives V = -GM(3R^2) / 2R^3 = -3GM / 2R. The potential is strictly non-zero and highly negative.

Discuss this Question (0)

No comments yet. Be the first to start the discussion!

Practice More Physics Questions

Question #1
The frequency of a sound wave is 500 Hz and wavelength 0.68 m. Speed is
A. 34 m/s
B. 170 m/s
C. 680 m/s
D. 340 m/s

Correct Answer: Option D


Explanation:
v = f λ = 500 × 0.68 = 340 m/s, typical speed of sound in air.

This question belongs to: Science Physics
Question #2
Specific heat capacity of water is 1 cal/g°C. Heat required to raise temperature of 200 g water from 25°C to 35°C is
A. 5000 cal
B. 200 cal
C. 2000 cal
D. 1000 cal

Correct Answer: Option C


Explanation:
Q = m c ΔT = 200 × 1 × 10 = 2000 cal.

This question belongs to: Science Physics
Question #3
A concave mirror forms a real, inverted, magnified image when object is
A. At infinity
B. Between P and F
C. Between F and C
D. At C

Correct Answer: Option C


Explanation:
Between F and C: image beyond C, magnified, inverted, real.

This question belongs to: Science Physics