List of top Physics Questions

Add \( 2.7 \times 10^{-5} \) to \( 4.5 \times 10^{-4} \) with due regard to significant figures
When a diode is reverse biased
An intrinsic semiconductor at \( T = 0 \, {K} \) behaves like
The half-life period of a radioactive element is 2 days. If \( \frac{1}{32} \) part of the initial amount remains undecayed after a time \( t \), then the value of \( t \) in days is
The electron concentration \( n_e \) and hole concentration \( n_h \) in semiconductor are related to the number of intrinsic charge concentration \( n_i \) as
In a nuclear fusion process, the masses of the fusing nuclei are \( M_A \) and \( M_B \). Then the mass of the product nucleus \( M_C \) is related to \( M_A \) and \( M_B \) as
The particle which is expected to be emitted along with \( Y \) in the following nuclear reaction is \[ { }^{198}_{80}X \rightarrow { }^{197}_{79}Y + ? \]
The number of de Broglie waves associated with Bohr electron when it completes one revolution in its third orbit is
Young’s double-slit experiment is carried out by using green, red and blue lights, one at a time. The fringe widths recorded are \( \beta_G \), \( \beta_R \) and \( \beta_B \) respectively. Then
Electromagnetic waves of frequency \( 5 \times 10^{14} \, {Hz} \) lie in the
In an LCR series resonance circuit driven by the alternating voltage \( V = V_0 \sin \omega t \), inductance \( L = 1 \, \mu H \), capacitance \( C = 1 \, \mu F \) and resistance \( R = 1 \, k\Omega \). The resonant angular frequency (in rad/s) is:
An alternative form of Biot-Savart's law is
The ratio of radii of the circular paths of a proton and a deuteron when projected perpendicular to the direction of a uniform magnetic field with the same speed is

The energy stored in the capacitor after closing the key K is 

Two like charges kept in air medium experience a force \( F \), when they are separated by a certain distance \( r \). When the same charges are kept in a dielectric medium at the same distance of the separation, the force between them is 0.5F. The dielectric constant of the medium is
If \( E \) is the electric field intensity between the plates of a charged parallel plate capacitor, energy stored per unit volume in it is (permittivity of free space = \( \epsilon_0 \))
Speed of a transverse wave on a stretched string under tension \(T\) and linear density \(\mu\) is
When the number of molecules per unit volume of an ideal gas is \( 0.8 \times 10^{24} \), the mean free path length for its molecules is \( 2.2 \times 10^{-5} \, {m} \). If the number of molecules per unit volume is \( 1.0 \times 10^{24} \), then the mean free path is
The work done by a gas on the system is zero in
If \( m_a \) and \( m_i \) are the slopes of the adiabatic and isothermal curves for an ideal gas, then \[ \left( \frac{c_p}{c_v} = \gamma \right) \]
The zeroth law of thermodynamics leads to the concept of
The elastic energy stored per unit volume in a stretched wire is: \[ \left( Y = \text{Young's modulus of the material of the wire}; \quad S = \text{stress acting on the wire} \right) \]
If the radii of two soap bubbles are respectively 2 cm and 3 cm, then the ratio of the excess pressures inside the soap bubbles is
A particle of 100 g mass is projected vertically up with a kinetic energy of 20 J. The maximum height reached by the particle is (\( g = 10 \) m/s\( ^2 \)) (neglecting air resistance).
For a smoothly running analog clock, the ratio of the angular velocity of the minute hand to the angular velocity of the hour hand is