List of top Physics Questions

The angular size of the central maxima due to a single slit diffraction (a = slit width) is:
A coil of 10 turns and resistance \(20\,\Omega\) is connected in series with a battery of resistance \(30\,\Omega\). The coil is placed with its plane perpendicular to a uniform magnetic field of induction \(10^{-2}\,\text{T}\). If it is now turned through an angle of \(60^\circ\) about an axis in its plane, the charge induced in the coil is (Area of coil \(=10^{-2}\,\text{m}^2\)):
Resolving power of a telescope will be more, if the diameter of the objective is:
The susceptibility of a magnetism at 300 K is \(1.2 \times 10^{-5}\). The temperature at which the susceptibility increases to \(1.8 \times 10^{-5}\) is:
A narrow beam of protons and deuterons, each having the same momentum, enters a region of uniform magnetic field directed perpendicular to their direction of momentum. The ratio of the radii of the circular paths described by them is:
Voltage and current in an AC circuit are given by \(V = 50\sin(50t)\,\text{V}\) and \(i = 50\sin(50t + \frac{\pi}{3})\,\text{mA}\). The power dissipated in the circuit is:
Two coaxial non-conducting cylinders of radius \(a\) and \(b\) are separated by a material of conductivity \(\sigma\) and a constant potential difference \(V\) is maintained between them by a battery. The current per unit length flowing from one cylinder to the other is:
Electric field in the region is given by \( \vec{E} = \left(\dfrac{M}{x^3}\right)\hat{i}\). The correct expression for the potential in the region is [assume potential at infinity is zero]:
A wire X is half the diameter and half the length of a wire Y of similar material. The ratio of resistance of X to that of Y is:
Two point dipoles \(p\hat{k}\) and \(\frac{p}{2}\hat{k}\) are located at \((0,0,0)\) and \((1\,\text{m},0,2\,\text{m})\) respectively. The resultant electric field due to the two dipoles at the point \((1\,\text{m},0,0)\) is:
Two balloons are filled with pure gases and other with air respectively. If the pressure and temperature of these balloons are same, then the number of molecules per unit volume is:
Two particles P and Q describe S.H.M. of same amplitude and same frequency along the same straight line. The maximum distance between the two particles is \(2A\). The initial phase difference between the particles is:
A tunnel is dug through the centre of the earth and a ball is released in it. It executes S.H.M. with time period:
When a string is divided into three segments of length \(l_1, l_2,\) and \(l_3\), the fundamental frequencies of these three segments are \(v_1, v_2,\) and \(v_3\) respectively. The original fundamental frequency of the string is:
In the kinetic theory of gases, which of these statements is/are true? (i) The pressure of a gas is proportional to the mean speed of the molecules. (ii) The root mean square speed of the molecules is proportional to the pressure. (iii) The rate of diffusion is proportional to the mean speed of molecules. (iv) The mean translational kinetic energy of a gas is proportional to its kelvin temperature.
One mole of \(O_2\) gas having a volume equal to \(22.4 \text{ litres}\) at \(0^\circ C\) and 1 atm is compressed isothermally so that its volume reduces to \(11.2 \text{ litres}\). The work done in this process is:
The wavelength of radiation emitted by a body depends upon:
A projectile is fired with a velocity \(u\) making an angle \(\theta\) with the horizontal. What is the magnitude of change in velocity when it is at the highest point?
A person with his hand in his pocket is skating on ice at the rate of \(10 \text{ m s}^{-1}\) and describes a circle of radius \(50 \text{ m}\). What is his inclination to vertical? \((g = 10 \text{ m s}^{-2})\)
For the equation of force \(F = Aa^b d^c\), where \(F\) is the force, \(A\) is the area, \(v\) is the velocity and \(d\) is the density, the values of \(a, b\) and \(c\) are respectively:
A spherically symmetric gravitational system of particles has a mass density \[ \rho = \begin{cases} \rho_0 & \text{for } r \le R \\ 0 & \text{for } r > R \end{cases} \] where \(\rho_0\) is a constant. A test mass can undergo circular motion under the influence of the gravitational field of particles. Its speed \(v\) as a function of distance \(r\) \((0 < r < \infty)\) from the centre of the system is represented by:
A small block of mass \(m\) is kept on a rough inclined surface of inclination \(\theta\) fixed in an elevator. The elevator goes up with a uniform velocity \(v\) and the block does not slide on the wedge. The work done by the force of friction on the block in time \(t\) will be:
A rifle man, who together with his rifle has a mass of 100 kg, stands on a smooth surface and fires 10 shots horizontally. Each bullet has a mass 10 g and a muzzle velocity of 800 m s\(^{-1}\). The velocity which the rifle man attains after firing 10 shots is:
A train accelerating uniformly from rest attains a maximum speed of \(40 \text{ m s}^{-1}\) in 20 s. It travels at this speed for 20 s and is brought to rest with uniform retardation in further 40 s. What is the average velocity during the period?
The average mass of rain drops is $3.0 \times 10^{-5}$ kg and their average terminal velocity is $9\, m/s.$ Calculate the energy transferred by rain to each square metre of the surface at a place which receives $100\, cm$ of rain in a year.