List of top Physics Questions

Two identical bodies are made of a material for which the heat capacity increases with temperature. One of these is at $100^{\circ} C$ , while the other one is at $0^{\circ} C$. If the two bodies are brought into contact, then, assuming no heat loss, the final common temperature is -

The ratio of escape velocity at earth $v_e$ to the escape velocity at a planet $v_p$ whose radius and mean density are twice as that of earth is :

The potential differences across the resistance, capacitance and inductance are $80\, V$, $40\, V$ and $100\, V$ respectively in an $L-C-R$ circuit . The power factor of this circuit is

The potential difference \((V_A - V_B)\) between the points \(A\) and \(B\) in the given figure is

The molecules of a given mass of a gas have r.m.s velocity of $200 \, ms^{-1}$ at $27^{\circ} C$ and $1.0 \times 10^5 \, Nm^{-2}$ pressure. When the temperature and pressure of the gas are respectively, $127^{\circ} C$ and $0.05 \times 10^5 \, Nm^{-2}$, the r.m.s. velocity of its molecules in $ms^{-1}$ is

The magnetic susceptibility is negative for :

The interference pattern is obtained with two coherent light sources of intensity ratio n. In the interference pattern, the ratio $\frac{I_{max} - I_{min}}{I_{max} + I_{min}}$ will be

The charge flowing through a resistance $R$ varies with time t as $ Q = at - bt^2$ , where $a$ and $b$ are positive constants, The total heat produced in $R$ is :

The angle of incidence for a ray of light at a refracting surface of a prism is $45^{\circ}$. The angle of prism is $60^{\circ }$. If the ray suffers minimum deviation through the prism, the angle of minimum deviation and refractive index of the material of the prism respectively, are :

In a diffraction pattern due to a single slit of width 'a', the first minimum is observed at an angle $30^{\circ}$ when light of wavelength $5000 \mathring A $ is incident on the slit. The first secondary maximum is observed at an angle of :

Given the value of Rydberg constant is $10^7 \, m^{-1}$, the wave number of the last line of the Balmer series in hydrogen spectrum will be :

From a disc of radius R and mass M, a circular hole of diameter R, whose rim passes through the centre is cut. What is the moment of inertia of the remaining part of the disc about a perpendicular axis, passing through the centre ?

Coefficient of linear expansion of brass and steel rods are $\alpha_1$ and $\alpha_2$. Lengths of brass and steel rods are $ l_1$ and $l_2$ respectively. If $(l_2 - l_1)$ is maintained same at all temperatures, which one of the following relations holds good ?

At what height from the surface of earth the gravitation potential and the value of g are $- 5.4 \times 10^7 \, J \, kg^{-2}$ and $6.0 \, ms^{-2}$ respectively ? Take the radius of earth as $6400 \,km$ :

An inductor $20\, mH$, a capacitor $50\, \mu F$ and a resistor $40 \, \Omega $ are connected in series across a source of emf $V = 10 \, \sin \, 340\,t$. The power loss in A.C. circuit is :

An electron is moving in a circular path under the influence of a transverse magnetic field of $3.57 \times 10^{-2} T$. If the value of $e / m$ is $1.76 \times 10^{11} C / kg$, the frequency of revolution of the electron is

An astronomical telescope has objective and eyepiece of focal lengths $40\, cm$ and $4 \,cm$ respectively. To view an object $200\, cm$ away from the objective, the lenses must be separated by a distance :

An air column, closed at one end and open at the other, resonates with a tuning fork when the smallest length of the column is $50\,cm$. The next larger length of the column resonating with the same tuning fork is :

An air bubble in a glass slab with refractive index $1.5$ (near normal incidence) is $5\,cm$ deep when viewed from one surface and $3\,cm$ deep when viewed from the opposite face. The thickness (in cm) of the slab is

A uniform magnetic field is restricted within a region of radius $r$. The magnetic field changes with time at a rate $\frac{d \vec{B}}{dt}$. Loop $1$ of radius $R > r$ enclosed the region $r$ and loop $2$ of radius $R$ is outside the region of magnetic field as shown in the figure below. Then the e.m.f. generated is

A uniform circular disc of radius 50 cm at rest is free to turn about an axis which is perpendicular to its plane and passes through its centre. It is subjected to a torque which produces a constant angular acceleration of $2.0 \, rad \, s^{-2}$. Its net acceleration in $ms^{-2}$ at the end of 2.0 s is approximately :

A siren emitting a sound of frequency $800\, Hz$ moves away from an observer towards a cliff at a speed of $15\,m\,s^{-1}$. Then, the frequency of sound that the observer hears in the echo reflected from the cliff is : (Take velocity of sound in air = $330 \, ms^{-1}$)

A refrigerator works between $4^{\circ}C$ and $30^{\circ}C$. It is required to remove $600\, calories$ of heat every second in order to keep the temperature of the refrigerated space constant. The power required is : $(Take\, 1 \,cal\, =\, 4.2 \,Joules)$

A piece of ice falls from a height h so that it melts completely. Only one-quarter of the heat produced is absorbed by the ice and all energy of ice gets converted into heat during its fall. The value of h is : [Latent heat of ice is $3.4 \times 10^5 \, J/kg$ and $g = 10 \, N/kg$]

A person can see clearly objects only when they lie between $50\,cm$ and $400\,cm$ from his eyes. In order to increase the maximum distance of distinct vision to infinity, the type and power of the correcting lens, the person has to use, will be