List of top Physics Questions asked in COMEDK UGET

Charge on electron is
A bat emitting an ultrasonic wave of frequency \( 4.5 \times 10^4 \, \text{Hz} \) at speed of \( 6 \, \text{m/s} \) between two parallel walls. The two frequencies heard by the bat will be
If \(K_1\) and \(K_2\) are maximum kinetic energies of photoelectrons emitted when lights of wavelengths \(\lambda_1\) and \(\lambda_2\), respectively incident on a metallic surface and \(\lambda_1 = 3\lambda_2\), then
A raft of density 600 g/m\(^3\) and mass 120 kg floats in water. How much weight can be put on the raft to make it just sink?
The escape velocity of a projectile on the earth's surface is 11.2 km/s. A body is projected out with thrice this speed. The speed of the body far away from the earth will be?
If kinetic energy of a body is increased by 300\%, then the percentage change in momentum will be
A copper and a steel wire of same diameter are connected end to end. A deforming force \( F_1 \) is applied to the wire which causes an elongation of 1 cm. The two wires will have
A point object is placed on the optic axis of a convex lens of focal length \( f \) at a distance of \( 2f \) to the left of it. The diameter of the lens is \( d \). An eye is placed at a distance of \( 3f \) to the right of the lens and a distance \( h \) below the optic axis. The maximum value of \( h \) to see the image is
During \( \alpha \)-decay, the atomic mass of parent nuclei is
For a CE transistor amplifier, the audio signal voltage across the collector resistance of \( 4 \, \text{k}\Omega \) is 5V. If the current amplification factor of the transistor is 100 and the base resistance is \( 2 \, \text{k}\Omega \), then the input signal voltage is
If the Earth were to spin faster, acceleration due to gravity at the poles
During the phenomenon of resonance, the amplitude of oscillation becomes large. The variation of g with angular velocity \( \omega \) is given by \[ g' = g - R\omega^2 \] If Earth were to spin faster, that is, angular velocity increases, then except at poles, the weight of bodies will decrease at all places.
If a heat engine is filled at temperature \( 27^\circ C \) and heat of 100 kcal is taken from the source at temperature \( 677^\circ C \), work done (in J) is
During the phenomenon of resonance

Carnot cycle of an engine is given below. What is the total work done by the gas in one cycle?

From the figure describing photoelectric effect, we may infer correctly that

Which of the following technique is NOT used for measuring small time intervals?
 

Centre of mass of the given system of particles will be at

A constant current flows from A to B as shown in the figure. What is the direction of current in the circle?

For the given electrical arrangement, what is the value of current \( I \)?

Two springs of force constants \( k_1 \) and \( k_2 \) are connected to a mass \( m \) as shown. The angular frequency of this configuration is:

Which graph shows the correct \( v \)–\( x \) graph of a freely falling body?

An optical fibre communication system works on a wavelength of \( 1.3 \, \mu m \). The number of subscribers it can feed, if a channel requires 20 kHz, are:
When the expansion of a gas occurs in vacuum and at constant volume, then:
In Young’s double slit experiment with sodium vapour lamp of wavelength 589 nm and slit 0.589 mm apart, the half angular width of the central maxima is