Physics

An ideal gas in a cylinder is separated by a piston in such a way that the entropy of one part is S? and that of the other part is S?. Given that S? > S?. If the piston is removed then the total entropy of the system will be :

The correct relation between α (ratio of collector current to emitter current) and β (ratio of collector current to base current) of a transistor is :

If the angular velocity of earth's spin is increased such that the bodies at the equator start floating, the duration of the day would be approximately :
[Take g = 10 ms⁻², the radius of earth, R = 6400*10³ m, Take π = 3.14]

The function of time representing a simple harmonic motion with time period of π/ω is:

The decay of a proton to neutron is :

The angular momentum of a planet of mass M moving around the sun in an elliptical orbit is L. The magnitude of the areal velocity of the planet is:

Three rays of light, red (R), green (G) and blue (B) are incident on the face PQ of a right angled prism PQR as shown in the figure. The refractive indices of material of the prism for red, green and blue wavelength are 1.27, 1.42 and 1.49 respectively. The colour of ray(s) emerging out of the face PR is

For an adiabatic expansion of an ideal gas, the fractional change in its pressure is equal to ( where γ is the ratio of specific heats):

A particle of mass m moves in a circular orbit under the central potential field, V(r) = -C/r, where C is a constant. The correct radius-velocity graph of the particle's motion is;

The time taken for the magnetic energy to reach 25% of its maximum value, when solenoid of resistance R, inductance L is connected to a battery, is: