1
WB JEE 2023
MCQ (Single Correct Answer)
+2
-0.5
Change Language

An earth's satellite near the surface of the earth takes about 90 min per revolution. A satellite orbiting the moon also takes about $$90 \mathrm{~min}$$ per revolution. Then which of the following is true?

[where $$\rho_{\mathrm{m}}$$ is density of the moon and $$\rho_{\mathrm{e}}$$ is density of the earth.]

A
$$\rho_{\mathrm{m}}<\rho_{\mathrm{e}}$$
B
$$\rho_{m}>\rho_{e}$$
C
$$\rho_{m}=\rho_{e}$$
D
No conclusion can be made about the densities.
2
WB JEE 2022
MCQ (Single Correct Answer)
+1
-0.25
Change Language

A body of mass m is thrown vertically upward with speed $$\sqrt3$$ ve, where ve is the escape velocity of a body from earth surface. The final velocity of the body is

A
0
B
2 ve
C
$$\sqrt3$$ ve
D
$$\sqrt2$$ ve
3
WB JEE 2021
MCQ (Single Correct Answer)
+2
-0.5
Change Language
An ideal gas of molar mass M is contained in a very tall vertical cylindrical column in the uniform gravitational field. Assuming the gas temperature to be T, the height at which the centre of gravity of the gas is located is (R$$\to$$universal gas constant)
A
$${{RT} \over g}$$
B
$${{RT} \over Mg}$$
C
MgR
D
RTg
4
WB JEE 2019
MCQ (Single Correct Answer)
+1
-0.25
Change Language
Assume that the earth moves around the sun in a circular orbit of radius R and there exists a planet which also move around the sun in a circular orbit with an angular speed twice as large as that of the earth. The earth of the orbit of the planet is
A
$${2^{ - 2/3}}$$ R
B
$${2^{ 2/3}}$$ R
C
$${2^{ - 1/3}}$$ R
D
$${R \over {\sqrt 2 }}$$
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