List of top Physics Questions

Two projectiles of identical mass are projected with same initial speed $u$ and angle $\alpha$ in the same plane. They collide at the highest point of their trajectories and stick to each other. Which statement is correct? 

A particle $P$ of mass $m$ is constrained to move on the surface of a cylinder under a force $-k\vec{r}$ as shown in the figure ($k$ is a positive constant). Neglect friction. Which of the following statements is correct?

Let the electric field in some region $R$ be given by $\vec{E} = e^{-y^2}\hat{i} + e^{-x^2}\hat{j}$. From this we conclude that
 

In presence of magnetic field $\vec{B}\hat{j}$ and electric field $(-E)\hat{k}$, a particle moves undeflected. Which statement is correct?
 

A particle of mass $m$ moves in the positive $x$ direction under the potential $V(x)=\frac{1}{2}kx^{2}+\frac{\lambda}{2x^{2}}$. If the particle is slightly displaced from equilibrium, the angular frequency $\omega$ is ............... (Give answer in units of $\sqrt{k/m}$ as an integer.)
 

A planet has the same average density as Earth but only $1/8$ the mass of Earth. If $g_p$ and $g_e$ are the surface gravities on the planet and Earth, then $\frac{g_p}{g_e} =$ ............ (Specify your answer up to one digit after decimal.)
 

In a grating with grating constant $d = a + b$, where $a$ is the slit width and $b$ is the separation between the slits, the diffraction pattern has the fourth order missing. The value of $\frac{b}{a}$ is ........... (Specify your answer as an integer.)
 

Consider an electromagnetic plane wave $\vec{E}=E_0(\hat{t}+b\hat{y})\cos\left[\frac{2\pi}{\lambda}(ct-(x-\sqrt{3}y))\right]$, where $\lambda$ is the wavelength and $c$ is the speed of light. The value of $b$ is ............. (Specify answer up to two digits after the decimal point.)
 

For the following circuit, the collector voltage with respect to ground will be .............. V. (Emitter diode voltage is 0.7 V and $\beta_{DC}$ of the transistor is large.) (Specify your answer in volts up to one digit after the decimal point.) 

For the given circuit, the value of base current $I_b$ of the npn transistor is ........... mA. ($\beta$ is the current gain and assume the Op-Amp as ideal.) (Specify your answer in mA up to two digits after decimal.) 

A monoatomic ideal gas undergoes a closed cycle shown in the P–V diagram. The ratio $\frac{P_2}{P_1}$ is ........... (Specify your answer up to two digits after the decimal point.)

Using the sublimation relation $\log_{10}(P)=\frac{C_1}{T}+C_2$ for zinc, with $C_1=6790$ K, $C_2=9$, compute the latent heat of sublimation using the Clausius–Clapeyron equation. (Specify answer in kJ/mol up to one digit after decimal.)
 

A system of 8 non-interacting electrons is confined by a 3-dimensional potential $V(r)=\frac{1}{2}m\omega^2 r^2$. The ground state energy of the system in units of $\hbar\omega$ is ............ (Specify your answer as an integer.)

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.)