List of top Physics Questions

A body of mass 1 kg moves in an elliptical orbit with semi-major axis 1000 m and semi-minor axis 100 m. The orbital angular momentum is 100 kg m$^2$ s$^{-1}$. The time period of motion is ............. hours. (Specify answer up to two digits after the decimal point.)
 

A syringe is used to exert 1.5 atmospheric pressure to release water horizontally. The speed of water immediately after ejection is ............ m s$^{-1}$. (Take 1 atmospheric pressure = $10^5$ Pa, density of water = $10^3$ kg m$^{-3}$.) (Specify your answer in m s$^{-1}$ as an integer.) 
 

A syringe is used to exert 1.5 atmospheric pressure to release water horizontally. The speed of water immediately after ejection is .............. m s$^{-1}$. (Take 1 atmospheric pressure = $10^5$ Pa, density of water = $10^3$ kg m$^{-3}$.) (Specify your answer in m s$^{-1}$ as an integer.)
 

A particle of mass $m$ moves in a circular orbit with $x = R\cos(\omega t)$ and $y = R\sin(\omega t)$ observed in inertial frame $S_1$. Another frame $S_2$ moves with velocity $\vec{v} = \omega R \hat{i}$ with respect to $S_1$, and origins coincide at $t=0$. The angular momentum at $t = \frac{2\pi}{\omega}$ as observed in $S_2$ about its origin is $(mR^2\omega)x$. Then $x$ is ............. (Specify answer up to two digits after decimal.)

Rod $R_1$ has rest length 1 m and rod $R_2$ has rest length 2 m. $R_1$ and $R_2$ move with velocities $+v\hat{i}$ and $-v\hat{i}$ respectively relative to the lab. If $R_2$ has a length of 1 m in the rest frame of $R_1$, $\frac{v}{c}$ is ................... (Specify answer up to two digits after decimal.)

In the following circuit, $RC$ is much larger than the input period. Assume diode is ideal and $R$ is large. The dc output voltage across $R$ will be .............. V. (Specify answer up to one digit after the decimal point.) 

For a metal, electron density is $6.4\times10^{28}\ \mathrm{m}^{-3}$. The Fermi energy is ................. eV. (Specify answer up to one digit after the decimal point.)
 

Two events occur in frame $S$ at $(t_1 = 0,\ r_1 = 0)$ and $(t_2 = 0,\ x_2 = 10^8\mathrm{m}, y_2 = 0, z_2 = 0)$. Another frame $S'$ moves with $v = 0.8c$ relative to $S$. The time difference $(t_2' - t_1')$ in $S'$ is ................... s. (Specify answer up to two digits after decimal.)
The moon moves around the earth in a circular orbit with a period of 27 days. If $R = 6.4 \times 10^6$ m is Earth's radius and $g = 9.8$ m/s$^2$, and if $D$ is the moon's orbital radius, find $D/R$. (Specify answer up to one digit after decimal point.)
The lattice constant of NaCl crystal is $0.563$ nm. X-rays of wavelength $0.141$ nm are diffracted by this crystal. The angle at which the first order maximum occurs is .......... degrees. (Specify answer up to two digits after decimal.)
Which of the combinations of crystal structure and coordination number is correct?
In a pn junction, dopant concentration on p-side is higher than n-side. Which statements are correct when the junction is unbiased?
Two beams of visible light (400–700 nm) interfere at a point. The optical path difference is 5000 nm. Which wavelength interferes constructively?
Which of the following relations is (are) true for thermodynamic variables?
A raindrop falls under gravity and captures water molecules from the atmosphere. Its mass changes at the rate $\lambda m(t)$, where $\lambda$ is a positive constant and $m(t)$ is the instantaneous mass. Assume gravity is constant and captured water is at rest before capture. Which of the following statements is correct?
Consider the transformation to a new set of coordinates $(\xi,\eta)$ from rectangular coordinates $(x,y)$, where $\xi=2x+3y$ and $\eta=3x-2y$. In the $(\xi,\eta)$ coordinate system, the area element $dx\,dy$ is
The Boolean expression $(AB)(\bar{A}+B)(A+\bar{B})$ can be simplified to
A disc of radius $R_1$ having uniform surface density has a concentric hole of radius $R_2<R_1$. If its mass is $M$, the principal moments of inertia are
Consider two waves $y_1=a\cos(\omega t-kz)$ and $y_2=a\cos[(\omega+\Delta \omega)t-(k+\Delta k)z]$. The group velocity of the superposed wave will be ($\Delta \omega \ll \omega$ and $\Delta k \ll k$)
Consider a convex lens of focal length $f$. A point object moves towards the lens along its axis between $2f$ and $f$. If the speed of the object is $V_o$, then its image would move with speed $V_i$. Which of the following is correct?
A rectangular loop of dimensions $l$ and $w$ moves with a constant speed $v$ through a region containing a uniform magnetic field $B$ directed into the paper and extending a distance of $4w$. Which of the following figures correctly represents the variation of emf $(\varepsilon)$ with the position $(x)$ of the front end of the loop?
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The equation of state for one mole of a non-ideal gas is given by $PV = A\left(1 + \dfrac{B}{V}\right)$, where the coefficients $A$ and $B$ are temperature dependent. If the volume changes from $V_1$ to $V_2$ in an isothermal process, the work done by the gas is
Consider an ensemble of thermodynamic systems, each of which is characterized by the same number of particles, pressure and temperature. The thermodynamic function describing the ensemble is
The plane of polarisation of a plane-polarised light rotates by $60^\circ$ after passing through a wave plate. The pass-axis of the wave plate is at an angle $\alpha$ with respect to the plane of polarisation of the incident light. The wave plate and $\alpha$ are
An ideal gas consists of three dimensional polyatomic molecules. The temperature is such that only one vibrational mode is excited. If $R$ denotes the gas constant, then the specific heat at constant volume of one mole of the gas at this temperature is