List of top Physics Questions asked in KEAM

The thickness of the depletion layer on either side of the p-n junction is of the order of
If the conductivity of the material lies in the range \(10^2 - 10^8 \, \Omega^{-1}m^{-1}\), then it is a
An external voltage \( V \) is supplied to a semiconductor diode having built-in potential \( V_0 \). The effective barrier height under forward bias is
If the initial decay rate of a radioactive sample is \( R_0 \), then the decay rate after a half-life time \( T_{1/2} \) is
In gamma emission, the nucleus emits
If the maximum number of neighbours of a nucleon within the range of nuclear force is \( p \) and \( k \) is a constant, then the binding energy per nucleon is approximately:
The energy required to excite the hydrogen atom from its first excited state to second excited state is:
The process by which the electrons can come out of the metal in a spark plug is:
A particle having mass 2000 times that of an electron travels with a velocity thrice that of the electron. The ratio of the de Broglie wavelength of the particle to that of the electron is
In a single slit diffraction experiment, the width of the slit and the wavelength of the light are respectively 5 mm and 500 nm. If the focal length of the lens is 20 cm, then the size of the central bright fringe will be
If the power of a lens is +4 D, then the lens is a
When two coherent sources each of individual intensity \( I_0 \) interfere, the resultant intensity due to constructive and destructive interference are respectively
The radiations used in LASIK eye surgery are:
If the total momentum delivered to a surface by an EM wave is \(3 \times 10^{-4}\) kg m/s, then the total energy transferred to this surface is:
The reactance of an induction coil of 4 H for a dc current (in \( \Omega \)) is:
When a current passing through a coil changes at a rate of 30 A s\(^{-1}\), the emf induced in the coil is 12 V. If the current passing through this coil changes at a rate of 20 A s\(^{-1}\), the emf induced in this coil is:
Which one of the following statement is INCORRECT?
A long straight wire carrying a current 3 A produces a magnetic field \( B \) at a certain distance. The current that flows through the same wire will produce a magnetic field \( \frac{B}{3} \) at the same distance is:
Torque on a coil carrying current \( I \) having \( N \) turns and area of cross section \( A \) when placed with its plane perpendicular to a magnetic field \( B \) is:
If a cell of 12 V emf delivers 2 A current in a circuit having a resistance of 5.8 \(\Omega\), then the internal resistance of the cell is:
n number of electrons flowing in a copper wire for 1 minute constitute a current of 0.5 A. Twice the number of electrons flowing through the same wire for 20 s will constitute a current of:
The resistance of a wire at 0 °C is 4 \(\Omega\). If the temperature coefficient of resistance of the material of the wire is \(5 \times 10^{-3} / ^\circ C\), then the resistance of a wire at 50 °C is:
Three capacitances 1 \(\mu\)F, 4 \(\mu\)F, and 5 \(\mu\)F are connected in parallel with a supply voltage. If the total charge flowing through the capacitors is 50 \(\mu\)C, then the supply voltage is:
The product of the total electric flux emanating from a closed surface enclosing a charge \( q \) in free space is (\( \epsilon_0 \) - electrical permittivity of free space):
If the fundamental frequency of the stretched string of length 1 m under a given tension is 3 Hz, then the fundamental frequency of the stretched string of length 0.75 m under the same tension is: