List of top Physics Questions

 The maximum focal length of convex lens is for: 
 

The path of scattered \( \alpha \)-particle is: 
 

The Louis de Broglie wavelength of a particle having kinetic energy E is:

A moving charge produces: 
 

Electric charges are uniformly distributed in a small volume. The flux of electric field through a spherical surface of radius 2 cm surrounding the total charge is 10 V x m. The flux over a sphere of radius 4 cm will be:

Calculate the conductivity of an n-type semiconductor from the following data: Density of conduction electrons = \( 8 \times 10^{13} \, \text{cm}^{-3} \) Density of holes = \( 5 \times 10^{12} \, \text{cm}^{-3} \) Mobility of electrons = \( 2.3 \times 10^4 \, \text{cm}^2/\text{V-s} \) Mobility of holes = \( 100 \, \text{cm}^2/\text{V-s} \)
Explain postulates of Bohr's model for Hydrogen atom. Show the number of lines in the (A) emission and (B) absorption spectra of Hydrogen atom corresponding to transition between energy states \(n = 1\) and \(n = 4\).
Explain image formation in a reflecting telescope with the help of a ray diagram. Compare its qualities with a refracting telescope.
Calculate the following in the given circuit:
(A) The equivalent capacitance of the circuit.
(B) The charge on \( 3 \, \mu\mathrm{F} \) and \( 2 \, \mu\mathrm{F} \) capacitors.
\includegraphics[]{equivalent capac.PNG}

State and explain Gauss's law in electrostatics. Using it, find the electric field due to a uniformly charged thin spherical shell (charge = q and radius = R) at 

(A) external point of shell 

(B) internal point of shell 

(C) on the surface of shell. 
 

Find the maximum magnitude of velocity and linear momentum of a photoelectron emitted when light of wavelength 4000 Ã… falls on a metal having work function 2.5 eV. 
 

What is interference of light? Mention the condition for (A) constructive and (B) destructive interference. 
 

Explain Maxwell's displacement current and write its equation. What is the phase difference between it and the conduction current? 
 

A coil has a resistance of 10 Ω and inductance of 0.4 Henry. It is connected to an AC source of 6.5 V, 30 Hz. Find the average power consumed in the circuit.

What is the value of resistance of ideal ammeter and ideal voltmeter? Why are an ammeter and a voltmeter respectively connected in series and parallel in a circuit? 
 

Define Mutual Inductance. Show that Henry = Newton Meter / Ampere².

In the given circuit, find the potential difference between \( A \) and \( B \). 
 

What is total internal reflection and critical angle? What is the working principle of Optical Fibre. 
 

The intensity of the magnetic field \( B \) due to a current-carrying circular coil of radius 12 cm at its center is \( 0.5 \times 10^{-4} \, \text{Tesla} \) perpendicular to the plane of the coil upward. Calculate the magnitude and direction of current flowing in the coil. 
 

Deduce the formula of torque on an electric dipole placed in a uniform electric field. 
 

Calculate the energy equivalence of unified atomic mass unit. 
 

Define the 'wavefront' of a wave. 
 

Ionisation energy of Hydrogen atom is 13.6 eV. In a state where \( n = 2 \), what will be ionisation energy of its electron? 
 

Deduce the dimensional equation of self-inductance. 
 

State Ampere's Circuital Law.