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

State Faraday's laws of electromagnetic induction.

State Lenz’s Law.

A circular coil of 250 turns and diameter 18 cm carries a current of 12A. What is the magnitude of magnetic moment associated with the coil?

On the basis of Huygens' wave theory of light prove that velocity of light in a rarer medium is greater than velocity of light in a denser medium.

The equation of simple harmonic progressive wave is given by `y=0.05sinpi[20t-x/6]` where all quantities are in S. I. units. Calculate the displacement of a particle at 5 m from origin and at the instant 0.1 second.

Show that the orbital magnetic dipole moment of a revolving electron is `(eVr)/2`

An ideal voltmeter has _______.

(A) low resistance

(b) high resistance

(C) infinite resistance

(D) zero resistance

Write the functions of the following in communication systems:

Transmitter

Write the functions of the following in communication systems:

Receiver

In a damped harmonic oscillator, periodic oscillations have _______ amplitude.

(A) gradually increasing

(B) suddenly increasing

(C) suddenly decreasing

(D) gradually decreasing

A sine wave of wavelength λ is travelling in a medium. What is the minimum distance between two particles of the medium which always have the same speed?

(A)`lambda`

(B)`lambda/2`

(C)`lambda/3`

(D)`lambda/4`

Prove that root mean square velocity of gas molecule is directly proportional to the square root of its absolute temperature.

A solid sphere of mass 1 kg rolls on a table with linear speed 2 m/s, find its total kinetic energy.

The total energy of free surface of a liquid drop is 2π times the surface tension of the liquid. What is the diameter of the drop? (Assume all terms in SI unit).

Explain how moving coil galvanometer is converted into a voltmeter. Derive the necessary formula.

A rectangular coil of a moving coil galvanometer contains 100 turns, each having area
15 cm². It is suspended in the radial magnetic field 0.03 T. The twist constant of suspension
fibre is 15 x 10^-10 N-m/degree. Calculate the sensitivity of the moving coil galvanometer.

An electron in an atom revolves around the nucleus in an orbit of radius 0.53 Å. If the frequency of revolution of an electron is 9 x10⁹ MHz, calculate the orbital  angular momentum

[Given : Charge on an electron = 1.6 x 10^–19 C; Gyromagnetic ratio = 8.8 x 10¹⁰ C/kg; π = 3.142]

If the angular speed of the earth is 7.26 x 10^–5 rad/s and radius of the earth is 6,400 km,
calculate the change in weight of 1 kg of mass taken from equator to pole.

At what temperature will average kinetic energy of gas be exactly half of its value at N.T.P.?

Define surface tension and surface energy.