List of top Physics Questions asked in Maharashtra Class XII

State Einstein's photoelectric equation and mention physical significance of each term involved in it. The wavelength of incident light is 4000Å. Calculate the energy of incident photon.
Diameter of a water drop is 0.6 mm. Calculate the pressure inside a liquid drop. (T = 72 dyne/cm, atmospheric pressure = \(1.013 \times 10^5\) N/m\(^2\))
A conducting bar is rotating with constant angular speed around a pivot at one end in a uniform magnetic field perpendicular to its plane of rotation. Obtain an expression for the rotational e.m.f. induced between the ends of the bar.
A flywheel of a motor has mass 100 kg and radius 1.5 m. The motor develops a constant torque of 2000 Nm. The flywheel starts from rest. Calculate the work done during the first 4 revolutions.
Obtain an expression for practical determination of end correction -- (i) for a pipe open at both ends and (ii) for a pipe closed at one end.
An electron in hydrogen atom stays in its second orbit for \(10^{-8}\) s. How many revolutions will it make around the nucleus in that time? [ Given : \(e = 1.6 \times 10^{-19}\) C, \(m = 9.1 \times 10^{-31}\) kg ]
Derive an expression for law of radioactive decay. Define one becquerel (Bq).
Derive an expression for law of radioactive decay. Define one becquerel (Bq).
In a thermodynamic system, define -- (a) Mechanical equilibrium (b) Chemical equilibrium and (c) Thermal equilibrium
State the advantages of a potentiometer over a voltmeter.
In a series LCR circuit, if resistance, inductive reactance and capacitive reactance are 3\(\Omega\), 8\(\Omega\) and 4\(\Omega\) respectively, calculate phase difference between voltage and current.
A gas of 0.5 mole at 300 K expands isothermally from an initial volume of 2.0 litre to a final volume of 6.0 litre. What is the work done by gas?
Obtain an expression for the period of a bar magnet vibrating in a uniform magnetic field, performing S.H.M.
In a thermodynamic system, define -- (a) Mechanical equilibrium (b) Chemical equilibrium and (c) Thermal equilibrium
Calculate the energy radiated in one minute by a perfectly black body of surface area 200 cm\(^2\) when it is maintained at 127\(^{\circ}\)C.
Two coils having self inductances 60 mH each, are coupled with each other. If the coefficient of coupling is 0.75, calculate the mutual inductance between them.
Explain harmonics and overtones.
What do you mean by a thermodynamic system?
What is the work done by an external uniform magnetic field perpendicular to the velocity of a moving charge?
Find kinetic energy of 1 litre of an ideal gas at S.T.P.
The gate which produces high output, when its both inputs are high is --
An electron, a proton, an \(\alpha\)-particle and a hydrogen atom are moving with the same kinetic energy. The associated de-Broglie wavelength will be longest for --
Which of the following equations gives correct expression for the internal resistance of a cell by using potentiometer?
A transformer increases an alternating e.m.f. from 220V to 880V. If primary coil has 1000 turns, the number of turns in the secondary coil are .............

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