A geostationary satellite is orbiting the earth at a height of 5R above that surface of the earth, R being the radius of the earth. The time period of another satellite in hours at a height of 2R from the surface of the earth is
5
10
A spherical planet has a mass Mp and diameter Dp. A particle of mass m falling freely near the surface of this planet will experience an acceleration due to gravity, equal to
4GMp/Dp2
GMpm/Dp2
GMpm/ Dp2
GMpm/ Dp2
An alternating electric field of frequency v is applied across the dees (radius =R ) of a cyclotron that is being used to accelerate protons (mass = m). The operating magnetic field (B) used in the cyclotron and the kinetic energy (K) of the proton beam, produced by it are given by
Two sphere A and B of masses m1 and m2 respectively collide. A is at rest initially and B is moving with velocity v along the x -axis. After the collision, B has a velocity v/2 in a direction perpendicular to the original direction. The mass A moves after collision in the direction
same as that of B
opposite to that of B
If the radius of a star is R and it acts as a black body, what would be the temperature of the star, in which the rate of energy production is Q?
Q/4πR2σ
(Q/4πR2σ)-1/2
(4πR2Q/σ)1/4
(4πR2Q/σ)1/4
The damping force on an oscillator is directly proportional to the velocity. The units of the constant of proportionality are
kg ms-1
kg ms-2
kgs-1
kgs-1
Liquid oxygen at 50 K is heated to 3000 K at a constant pressure of 1 atm. The rate of heating is constant. which one of the following graphs represents the variation of temperature with time?
One mole of an ideal gas goes from an initial state A to final state B via two processes. It first undergoes isothermal expansion from volume V to 3V and then its volume is reduced from 3V to V at constant pressure. The correct p-V diagram representing the two processes is
A solid cylinder of mass 3 kg is rolling on a horizontal surface with velocity 4 ms-1. It collides with horizontal springs of force constant 200 Nm-1. The maximum compression produced in the spring will be
0.5 m
0.6 m
0.7 m
0.7 m
A thermodynamic system is taken through the cycle ABCD as shown in a figure. Heat rejected by the gas during the cycle is
2 pV
4 pV
1/2 pV
1/2 pV
A.
2 pV
For given cyclic process, ΔU = 0
therefore, Q =W
Also, W = - area enclosed by the curve
= AB x AD
= (2p-p) (3V-V)
=-p x 2V
therefore,
Heat rejected = 2pV