List of top Physics Questions

The magnitudes of two vectors are A and B (A>B). If the maximum resultant magnitude of the two vectors is ‘n’ times their minimum resultant magnitude, then \(\frac{A}{B} =\)
The ratio of the displacements of a freely falling body during second and fifth seconds of its motion is
The dimensional formula of Planck’s constant is
An unpolarised beam of light incidents on a group of three polarising sheets arranged such that the angle between the axes of any two adjacent sheets is $30^\circ$. The ratio of the intensities of polarised light emerging from the second and third sheets is
The wavelength of spectral line corresponding to electron transition \( n = 3 \) to \( n = 2 \) for \( \text{Li}^{2+} \) ion is \( \lambda \,\text{nm} \). What is the wavelength (in nm) corresponding to electron transition \( n = 4 \) to \( n = 1 \) for \( \text{He}^+ \) ion?
The minimum length of an antenna to transmit a signal of frequency \( 3 \text{ kHz} \) is
If the collector and base currents of a transistor in common emitter configuration are 5 mA and 50 \(\mu\)A, then the current amplification factor of the transistor is
If a capacitor of 500 nF is connected to an AC source of frequency 1 kHz, then the capacitive reactance of the capacitor is
In the circuit of resistors shown in the figure, the effective resistance between points A and B is
effective resistance between points A and B is
The capacitance of a solid sphere of radius 18 cm is
A spherical black body of radius 12 cm at a temperature of \(T\) K radiates a power of 400 W. If the radius of the sphere is doubled and absolute temperature is halved, then the power radiated by the body is
Three point charges +10 µC, +20 µC, and +40 µC are placed at the vertices of an equilateral triangle of side 1 m. The electrostatic potential energy of the system of the charges is
The focal length of a convex lens immersed in a liquid of refractive index 1.2 is \( f_1 \) and its focal length when immersed in another liquid of refractive index 1.25 is \( f_2 \). If the refractive index of the material of the lens is 1.5, then \( f_1 : f_2 = \)
During adiabatic expansion process, if the temperature of 4 moles of a monoatomic gas is decreased by \(100^\circ C\), then the work done by the gas is
(Universal gas constant \(R = 8.3 \, \text{J/mol·K}\))
If two temperatures on Celsius scale differ by \( 25^\circ \), then the difference of those two temperatures on Fahrenheit scale is
For a body in simple harmonic motion, the relation between force \( F \) (in Newton) acting on the body and its displacement \( y \) (in metre) is given as \( F + 3y = 0 \). If the time period of oscillation of the body is \( \pi \) s, then its mass is
If the amplitudes of a damped harmonic oscillator at times 3 and 6 seconds are 6 cm and 4 cm respectively, then the initial amplitude of the oscillator is
A body of mass 2 kg starts moving from the origin (0, 0) with an initial velocity of \( (4\hat{i} + 4\hat{j})\ \text{ms}^{-1} \). A constant force of \( -20\hat{j} \ \text{N} \) is applied on the body. When the Y-coordinate of the position of the body becomes zero again, then its X-coordinate is
If a body is projected horizontally from a height of 50 m with a speed of 20 m/s, then its speed after a time of 1.5 s is
(Acceleration due to gravity \( g = 10\ \text{m/s}^2 \))
A person walks up an escalator at rest in a time of 60 s. When standing on the same escalator now moving with a uniform speed, he is carried up in a time of 30 s. The time taken for him to walk up the moving escalator is
In a transistor, if the emitter and collector currents are respectively 2 mA and 1.95 mA, then the base current is
The current in a coil decreases from 5 A to zero in a time of 0.1 s. If an average emf of 200 V is induced, then the self inductance of the coil is
If the radius of a circular coil is doubled and the number of turns is halved, then the magnetic field at the centre of the coil for the same current is
In a hydrogen atom, if an electron makes a transition from the fourth orbit to the second orbit, then the wavelength of the emitted radiation is: (R = Rydberg constant)
If a particle of mass \( 6 \times 10^{-30} \) kg is moving with a speed of \( 5.5 \times 10^5 \text{ m s}^{-1} \), then the de Broglie wavelength of the particle is
(Planck's constant = \( 6.6 \times 10^{-34} \text{ J s} \))