Q. A point $P$ is lying at a distance $r(< a)$ from the centre of shell of radius $a$. If $g$ and $V$ be the gravitational field and potential at the point $P$ then :

Gravitation Report Error

A

$g=0$

B

$g=-\frac{G M}{r^{2}}$

C

$V=0$

D

$V=-\frac{G M}{a}$

Solution:

The field inside the shell is zero and so potential inside the shell is constant and equal to the value that exists at the surface i.e. $-\frac{G M}{a}$.

Questions from Gravitation

1. The binding energy of a satellite of mass m in a orbit of radius r is (R = radius of earth, g = acceleration due to gravity)

Maharashtra CET 2005

2. Assertion : Planet is a heavenly body revolving round the sun.
Reason : Star is luminous body made of gaseous material.

AIIMS 2002

3. If $W_1$, $W_2$ and $W_3$ represent the work done in moving a particle from $A$ to $B$ along three different paths $1$, $2$ and $3$ (as shown in fig) in the gravitational field of the point mass $'m'$. Find the correct relation between $'W'_1$, $'W_2'$ and $'W_3'$

Maharashtra CET 2019

4. A projectile is fired from the surface of the Earth of radius $R$ with a velocity $\eta v_{e}$ , where $v_{e}$ is the escape velocity and $\eta < 1$ . Neglecting the air resistance, the orbital velocity of the projectile is

NTA Abhyas 2020

5. The effect of rotation of the Earth on the value of acceleration due to gravity is

NTA Abhyas 2020

Physics Most Viewed Questions

1. If $E$ and $G$ respectively denote energy and gravitational constant, then $\frac{ E }{ G }$ has the dimensions of:

NEET 2021 Physical World, Units and Measurements

2. The de Broglie wavelength of an electron moving with kinetic energy of $144 \,eV$ is nearly

NEET 2020 Dual Nature of Radiation and Matter

3. A car starts from rest and accelerates at $5\, m / s ^{2}$ At $t=4\, s$, a ball is dropped out of a window by a person sitting in the car. What is the velocity and acceleration of the ball at $t =6\, s$ ? (Take $\left. g =10\, m / s ^{2}\right)$

NEET 2021 Motion in a Straight Line

4. A wheel with $20$ metallic spokes each $1\, m$ long is rotated with a speed of $120\, rpm$ in a plane perpendicular to a magnetic field of $0.4\, G$. The induced emf between the axle and rim of the wheel will be, $(1 G = 10^{-4}\, T)$

NEET 2020 Electromagnetic Induction

5. A barometer is constructed using a liquid (density $= 760 \,kg/m^{3})$ What would be the height of the liquid column, when a mercury barometer reads $76\, cm$ ?
(density of mercury $= 13600 kg/m^{3})$

NEET 2020 Mechanical Properties of Fluids