HSC Science (General) १२ वीं कक्षा - Maharashtra State Board Question Bank Solutions for Physics

The thermal efficiency of a heat engine is 25%. If in one cycle the heat absorbed from the hot reservoir is 50000 J, what is the heat rejected to the cold reservoir in one cycle?

What are the steps through which a refrigerant goes in one complete cycle of refrigeration?

A sonometer wire under a tension of 40 N vibrates in unison with a tuning fork of frequency 384 Hz. Find the beat frequency when the tension in the wire is reduced by 0.21 N.

A blackbody at 327 °C, when suspended in a black enclosure at 27 °C, loses heat at a certain rate. Find the temperature of the body at which its rate of loss of heat by radiation will be half of the above rate. Assume that the other conditions remain unchanged. 

What does a heat engine consist of?

A short bar magnet of moment 0.5.A m² is suspended in a horizontal magnetic field of 1000 gauss such that it can rotate freely in a horizontal plane. Calculate (i) the magnitude of the torque and (ii) the magnetic potential energy when its angular displacement with respect to the direction of the field is 10°.

The power factor of LCR circuit is ______.

What is a heat engine?

Mention any two elements of a heat engine.

One beat means that the intensity of sound should be ______.

The effective capacitor between A and B in the following circuit is ______.

Explain the theory of an AC circuit with a resistor. 

Explain the mechanism of a refrigerator with the help of a schematic diagram.

The coefficient of performance of a room air conditioner is 3. If the rate of doing work is 2 kW, the heat current is ______.

Which physical quantity of an atomic electron has the dimensions same as that of h?

Where is the power dissipated in an alternating current circuit?

Draw a neat labelled diagram of Ferry’s perfectly black body.

Define emissive power and coefficient of emmision of a body.

A metal sphere cools at the rate of 4°C / min. when its temperature is 50°C. Find its rate of cooling at 45°C if the temperature of surroundings is 25°C.

The resolving power of a telescope depends upon the ______.