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

Obtain an expression for average power dissipated in a series LCR circuit.
At what temperature the surface tension of a liquid becomes zero?
The power rating of a ceiling fan rotating with a constant torque of 2 Nm with an angular speed of 2\(\pi\) rad/s will be ............
"If two systems are each in thermal equilibrium with a third system, they are also in thermal equilibrium with each other." This statement refers to :
Using Newton's law of viscosity for streamline flow, derive an expression for coefficient of viscosity.
State the formula for magnetic induction produced by a current in a circular arc of a wire. Hence find the magnetic induction at the centre of a current carrying circular loop.
Which of the following materials belongs to diathermanous substance?
What is Ferromagnetism? Explain it on the basis of domain theory.
Distinguish between interference and diffraction of light. A double slit arrangement produces interference fringes for sodium light of wavelength 589 nm, that are 0.20 degree apart. What is the angular fringe separation if the entire arrangement is immersed in water? (R.I. of water = 1.33)
A solenoid of length \(\pi\) m and 5 cm in diameter has a winding of 1000 turns and carries a current of 5A. Calculate the magnetic field at its centre along the axis.
State any four uses of Van de Graaff generator. In a parallel plate air capacitor, intensity of electric field is changing at the rate of \(2 \times 10^{11}\) V/ms. If area of each plate is 20 cm\(^2\), calculate the displacement current.
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 galvanometer has a resistance of 50 \(\Omega\) and a current of 2 mA is needed for its full scale deflection. Calculate resistance required to convert it. (i) into an ammeter of 0.5 A range. (ii) into a voltmeter of 10 V range.
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.
Derive an expression for law of radioactive decay. Define one becquerel (Bq).
Derive an expression for law of radioactive decay. Define one becquerel (Bq).
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.
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 ]
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.
In a thermodynamic system, define -- (a) Mechanical equilibrium (b) Chemical equilibrium and (c) Thermal equilibrium
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.
State and prove Kirchhoff's law of heat radiation.
In a thermodynamic system, define -- (a) Mechanical equilibrium (b) Chemical equilibrium and (c) Thermal equilibrium
What is Brewster's law? Derive the formula for Brewster's angle.
State the advantages of a potentiometer over a voltmeter.