List of top Physics Questions

What is diffraction of light? Explain diffraction at a single slit and deduce the expression for the width of its central maxima.
A wire is cut across a flux of \( 0.2 \times 10^{-2} \) weber in 0.12 seconds. What is the e.m.f. induced in the wire?
A proton enters into a magnetic field of intensity \( 5 \times 10^{-2} \) Tesla with velocity \( 10^5 \, \text{m/s} \) at an angle of 30° with the field. Calculate the magnitude of force acting on the proton due to this field.
Define the coefficient of self-induction and find an expression for it for a solenoid.
Explain Biot-Savart's law for a small current-carrying conductor.
Write down at least three properties of nuclear force.
With the help of a circuit diagram, explain the V-I characteristics of a p-n junction in reverse biasing.
Derive an expression for the potential energy of a charged capacitor.
With the help of a circuit diagram, explain the V-I characteristics of a p-n junction in reverse biasing.
Find the total resistance of a circuit in which three resistances are connected in series.
Find the focal length of the combination of two thin lenses in contact.
Two lenses, one diverging of power 2D and the other converging of power 6D are combined together. Calculate the focal length and power of combination.
What are the factors which reduce the efficiency of a transformer?
What is resistance? Define SI unit of resistance.
Calculate the resistivity of the material of a conductor of length 3 m, area of cross section \( 0.2 \, \text{mm}^2 \) having a resistance of 2 \( \Omega \).
Calculate the Coulomb’s force between proton and electron separated by a distance of \( 0.8 \times 10^{-15} \) m.
Derive an expression for magnetic force. How is the direction of magnetic force determined?
What is displacement current?
Define threshold wavelength and frequency.
Why can’t two equipotential surfaces intersect each other?
The size of the mirror does not affect the nature of the image. (T/F)
Write an expression for mass defect.
The density of nuclear matter is independent of the size of the nucleus. (T/F)
Calculate the de-Broglie wavelength for electrons moving with speed of \( 10^5 \, \text{m/s} \).
Wheatstone bridge is used to measure: