List of top Physics Questions asked in Maharashtra Board Class XII Exam

Derive an expression for energy stored in a charged capacitor. A spherical metal ball of radius 15 cm carries a charge of 2μC. Calculate the electric field at a distance of 20 cm from the center of the sphere.

Draw a neat labelled diagram of Ferry's perfectly black body. Compare the rms speed of hydrogen molecules at 227°C with rms speed of oxygen molecules at 127°C. Given that molecular masses of hydrogen and oxygen are 2 and 32, respectively.

Distinguish between an ammeter and a voltmeter. (Two points each).
The displacement of a particle performing simple harmonic motion is \( \frac{1}{3} \) of its amplitude. What fraction of total energy is its kinetic energy?
 

Using the geometry of the double slit experiment, derive the expression for the fringe width of interference bands.

An alternating voltage is given by \( e = 8 \sin(628.4 t) \). 
Find:
(i) Peak value of e.m.f. 
(ii) Frequency of e.m.f. 
(iii) Instantaneous value of e.m.f. at time \( t = 10 \, {ms} \) 

What is a transformer? Explain the construction and working of a transformer. Derive the equation for a transformer.

Prove Mayer's relation: \( C_p - C_v = \frac{R}{J} \)

The radius of a circular track is 200 m. Find the angle of banking of the track, if the maximum speed at which a car can be driven safely along it is 25 m/s.

A current carrying toroid winding is internally filled with lithium having susceptibility \( \chi = 2.1 \times 10^{-5} \). What is the percentage increase in the magnetic field in the presence of lithium over that without it?

Derive an expression for the impedance of an LCR circuit connected to an AC power supply. Draw the phasor diagram.

Calculate the wavelength of the first two lines in the Balmer series of the hydrogen atom.

Derive an expression for the equation of stationary wave on a stretched string. Show that the distance between two successive nodes or antinodes is \( \frac{\lambda}{2} \).

What is an isothermal process? Obtain an expression for work done by a gas in an isothermal process.

Define surface energy of the liquid. Obtain the relation between the surface energy and surface tension.

Define the current gain \( \alpha_{DC} \) and \( \beta_{DC} \) for a transistor. Obtain the relation between them.

Define photoelectric effect and explain the experimental set-up of the photoelectric effect.

A circular coil of wire is made up of 200 turns, each of radius 10 cm. If a current of 0.5A passes through it, what will be the magnetic field at the centre of the coil?

Calculate the change in angular momentum of an electron when it jumps from the third orbit to the first orbit in a hydrogen atom.

Two tuning forks having frequencies 320 Hz and 340 Hz are sounded together to produce sound waves. The velocity of sound in air is 340 m/s. Find the difference in wavelength of these waves.

A horizontal force of 0.5 N is required to move a metal plate of area \( 10^{-2} \, {m}^2 \) with a velocity of \( 3 \times 10^{-2} \, {m/s} \), when it rests on \( 0.5 \times 10^{-3} \, {m} \) thick layer of glycerin. Find the viscosity of glycerin.

Derive an expression for maximum speed of a vehicle moving along a horizontal circular track.

An aircraft of wing span of 60 m flies horizontally in earth's magnetic field of \( 6 \times 10^{-5} \, {T} \) at a speed of 500 m/s. Calculate the e.m.f. induced between the tips of the wings of the aircraft.

What is a Light Emitting Diode? Draw its circuit symbol.

Explain Biot-Savart law.