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

Apparent frequency of the sound heard by a listener is less than the actual frequency of sound emitted by source. In this case _______.

(A) listener moves towards source

(B) source moves towards listener

(C) listener moves away from the source.

(D) source and listener move towards each other.

Obtain an expression for the induced e.m.f. in a coil rotating with uniform angular velocity in
uniform magnetic field. Plot a graph of variation of induced e.m.f. against phase (Θ = ωt) over one cycle.

State any four applications of Doppler effect

Define moment of inertia. State its SI unit and dimensions.

At which position of the plane of the rotating coil with the direction of magnetic field, the e.m.f. induced in the coil is maximum?

State Brewster’s law and show that when light is incident at polarizing angle the reflected and refracted rays are mutually perpendicular to each other.

Soft iron is used to make the core of the transformer because of its ______.

Which property of soft iron makes it useful for preparing electromagnet?

What should be retentivity and coercivity of permanent magnet?

Answer in brief.

Explain one application of electromagnet.

Compare resistance and reactance.

Answer in brief:

What are harmonics and overtones?

State two applications of Pascal's law.

Give an example of some familiar process in which heat is added to an object, without changing its temperature.

Answer in brief.

Why should a Carnot cycle have two isothermal two adiabatic processes?

An ideal gas is taken through an isothermal process. If it does 2000 J of work on its environment, how much heat is added to it?

A sound wave in a certain fluid medium is reflected at an obstacle to form a standing wave. The distance between two successive nodes is 3.75 cm. If the velocity of sound is 1500 m/s, find the frequency.

Two sound waves travel at a speed of 330 m/s. If their frequencies are also identical and are equal to 540 Hz, what will be the phase difference between the waves at points 3.5 m from one source and 3 m from the other if the sources are in phase?

A pipe closed at one end can produce overtones at frequencies 640 Hz, 896 Hz, and 1152 Hz. Calculate the fundamental frequency.

Find the fundamental, first overtone, and second overtone frequencies of a pipe, open at both the ends, of length 25 cm if the speed of sound in air is 330 m/s.