List of top Physics Questions

Light is an electromagnetic wave whose

When the observer moves towards the stationary source with velocity, $V_1$, the apparent frequency of emitted note is $F_1$. When the observer moves away from the source with velocity $V_1$, the apparent frequency is $F_2$. If $V$ is the velocity of sound in air and $\frac{F_{1}}{F_{2}} = 2$ then $\frac{V}{V_{1}}=$ ?

A mass $m_1$ connected to a horizontal spring performs $S.H.M.$ with amplitude $A$. While mass $m_1$ is passing through mean position another mass $m_2$ is placed on it so that both the masses move together with amplitude $A_1$. The ratio of $\frac{A_{1}}{A}$ is $\left(m_{2} < m_{1}\right)$

A screw gauge with a pitch of $0.5\, mm$ and a circular scale with $50$ divisions is used to measure the thickness of a thin sheet of Aluminium. Before starting the measurement, it is found that when the two jaws of the screw gauge are brought in contact, the $45^{th}$ division coincides with the main scale line and that the zero of the main scale is barely visible. What is the thickness of the sheet if the main scale reading is $0.5\, mm$ and the $25^{th}$ division coincides with the main scale line ?

In an oscillator, for sustained oscillations, Barkhausen criterion is $A\beta$ equal to ($A =$ voltage gain without feedback, $\beta =$ feedback factor)

A particle moves along a circle of radius ?$r$? with constant tangential acceleration. If the velocity of the particle is ?$?$? at the end of second revolution, after the revolution has started then the tangential acceleration is

A modulated signal $C_m(t)$ has the form $C_m(t)=30$ sin $300 \pi t + 10$ (cos $200 \pi t -$ cos $400 \pi t$). The carrier frequency $f_{c}$, the modulating frequency (message frequency) $f_{\omega}$, and the modulation index $\mu$ are respectively given by :

A bottle has an opening of radius $a$ and length $b$. A cork of length $b$ and radius $(a+ \Delta a)$ where $(\Delta a < < a)$ is compressed to fit into the opening completely (See figure). If the bulk modulus of cork is $B$ and frictional coefficient between the bottle and cork is $\mu$ then the force needed to push the cork into the bottle is :

A student measures the time period of $100$ oscillations of a simple pendulum four times. The data set is $90\, s, 91\, s, 95\, s$ and $92\, s$. If the minimum division in the measuring clock is $1 \,s$, then the reported mean time should be :

A and B are two parallel sided transparent slabs of refractive indices n$_1 $and n$_2$ respectively. A ray is incident at an angle $\theta$ on the surface of separation of A and B, and after refraction from B into air grazes the surface of B. Then

Hysteresis loops for two magnetic materials $A$ and $B$ are given below : These materials are used to make magnets for electric generators, transformer core and electromagnet core. Then it is proper to use :

Two cars are in a race. The white car passed the finishing point with a velocity $ v\, ms^{-1} $ more and took time $ t\, s $ less than the red car. If both the cars start from rest and travel with constant accelerations $ a_w $ , and $ a_r $ respectively, $ \frac{v}{t} $ is given

A particle moving with an initial velocity $ u\, ms^{-1} $ is retarded by a force at the rate of $ a = - k \sqrt v $ . where $ K $ is a positive constant and $ v $ is the instantaneous velocity. The particle comes to rest in a time given by

A particle moves with a uniform speed $ v $ and time period $ T $ in a circular path of radius $ r $ . If the speed of the particle is doubled, its new time period is

Choose the wrong statement

A given sample of an ideal gas occupies a volume $V$ at a pressure $P$ and absolute temperature $T$. The mass of each molecule of the gas is $m$. Which of the following gives the density of the gas ?

The kinetic energy of a particle executing simple harmonic motion is $ 1/6^{th} $ of its maximum value at a distance of $ 5 \,cm $ from its equilibrium position. The amplitude of its motion is

In a moving coil galvanometer, the coil having $ 500 $ turns and an average area of $ 4 \,cm^{2} $ carries a current of $ 0.1 \,A $ and is set parallel to a magnetic field with a torque of $ 0.15\, N \,m $ . The strength of the magnetic field is

An organ pipe open at both ends has fundamental frequency $ f $ in air. If the pipe is dipped vertically in water such that $ 1/4^{th} $ of its length is inside water, then the fundamental frequency of the air column in it is

The pair of rigid bodies with mass M and radius R, having the moment of inertia $\frac{MR^{2}}{2}$ can be

The operating point of transistor amplifier should be in

For a thin lens with radii of curvatures and $ R_{1} $ and $ R_{2} $ , refractive index $ n $ and focal length $ f $ , the factor $ \left(\frac{1}{R_{1}}-\frac{1}{R_{2}}\right) $ is equal to

The electric flux passing through $a$ cube of side $ a $ , which holds a charge $ q $ at one of its corners is

The angle between the linear momentum and angular momentum of a particle moving along a circle is

The distance of closest approach for an alpha nucleus of velocity $ v $ bombarding a stationary heavy nucleus target of charge $ Ze $ is directly proportional to