List of top Physics Questions asked in KCET

In the diagram shown, the Zener diode has a reverse breakdown voltage \( V_z \). The current through the load resistance \( R_L \) is \( I_L \). The current through the Zener diode is

A solid cube of mass \( m \) at a temperature \( \theta_0 \) is heated at a constant rate. It becomes liquid at temperature \( \theta_1 \), and vapor at temperature \( \theta_2 \). Let \( s_1 \) and \( s_2 \) be specific heats in its solid and liquid states respectively. If \( L \) and \( L_v \) are latent heats of fusion and vaporization respectively, then the minimum heat energy supplied to the cube until it vaporises is

Water flows through a horizontal pipe of varying cross-section at a rate of 0.314 m³/s. The velocity of water at a point where the radius of the pipe is 10 cm is

One mole of an ideal monatomic gas is taken round the cyclic process \( MNOM \). The work done by the gas is

The value of acceleration due to gravity at a height equal to half the radius of the Earth, from its surface

A body of mass 1 kg is suspended by a weightless string which passes over a frictionless pulley of mass 2 kg as shown in the figure. The mass is released from a height of 1.6m from the ground. With what velocity does it strike the ground?

A thick metal wire of density \( \rho \) and length \( L \) is hung from a rigid support. The increase in length of the wire due to its own weight

A ceiling fan is rotating around a fixed axle as shown. The direction of angular velocity is along

A block of certain mass is placed on a rough inclined plane. The angle between the plane and the horizontal is \( 30^\circ \). The coefficients of static and kinetic frictions between the block and the inclined plane are 0.6 and 0.5 respectively. Then the magnitude of the acceleration of the block is

Among the given pair of vectors, the resultant of two vectors can never be 3 units. The vectors are

Dimensional formula for activity of a radioactive substance is

A particle of mass 500 g is at rest. It is free to move along a straight line. The power delivered to the particle varies with time according to the following graph:

The upper level of valence band and lower level of conduction band overlap in the case of

A p-n junction diode is connected to a battery of emf 5.7 V in series with a resistor 5k \( \Omega \) such that it is forward biased. If the barrier potential of the diode is 0.7 V, neglecting the diode resistance, the current in the circuit is

An athlete runs along a circular track of diameter 80m. The distance travelled and the magnitude of displacement of the athlete when he covers \( \frac{3}{4} \) of the circle is (in m)

The natural logarithm of the activity \( R \) of a radioactive sample varies with time \( t \) as shown. At \( t = 0 \), there are \( N_0 \) undecayed nuclei. Then \( N_0 \) is equal to \([\text{Take} \ e^{7.5}] \)

Depletion region in an unbiased semiconductor diode is a region consisting of

The photoelectric work function for a photo metal is \( 2 \, \text{eV} \). Among the four wavelengths, the wavelength of light for which photoemission does not take place is

The ratio of area of first excited state to ground state of orbit of hydrogen atom is

In alpha particle scattering experiment, if \( v \) is the initial velocity of the particle, then the distance of closest approach is

The ratio of volume of \( \text{Al}^{27} \) nucleus to its surface area is (Given \( R_0 = 1.2 \times 10^{-15} \) m)

In Young's double slit experiment, an electron beam is used to produce interference fringes of width \( \beta_1 \). Now the electron beam is replaced by a beam of protons with the same experimental setup and same speed. The fringe width obtained is \( \beta_2 \). The correct relation between \( \beta_1 \) and \( \beta_2 \) is

Consider the nuclear fission reaction\( \text{n}^{1} + \text{U}^{235} \rightarrow \text{Ba}^{144} + \text{Kr}^{89} + 3 \text{n}.\) Assuming all the kinetic energy is carried away by the fast neutrons only and total binding energies of \( \text{U}^{235} \), \( \text{Ba}^{144} \), and \( \text{Kr}^{89} \) to be 1800 MeV, 1200 MeV, and 780 MeV respectively, the average kinetic energy carried by each fast neutron is (in MeV)

Light of energy \( E \) falls normally on a metal of work function \( W_0 \). The kinetic energies \( K \) of the photoelectrons are

Three polaroid sheets are co-axially placed as indicated in the diagram. Pass axes of the polaroids 2 and 3 make 30° and 90° with pass axes of polaroid sheet 1. If \( I_1 \) is the intensity of the incident unpolarised light entering sheet 1, the intensity of the emergent light through sheet 3 is