HSC Science (Computer Science) 12th Standard Board Exam - Maharashtra State Board Question Bank Solutions for Physics

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 ______.

Two copper spheres of radii 6 cm and 12 cm respectively are suspended in an evacuated enclosure. Each of them are at a temperature 15°C above the surroundings. The ratio of their rate of loss of heat is.................

1. 2:1
2. 1:4
3. 1:8
4. 8:1

Discuss the composition of two S.H.M.s along the same path having same period. Find the resultant amplitude and intial phase.