List of top Physics Questions

The radiation of energy \( E \) falls normally on a perfectly reflecting surface. The momentum transferred to the surface is:
216 small identical liquid drops each of surface area \( A \) coalesce to form a bigger drop. If the surface tension of the liquid is \( T \), the energy released in the process is
In a potentiometer, the area of cross-section of the wire is 4 cm\(^2\), the current flowing in the circuit is 1 A, and the potential gradient is 7.5 Vm\(^{-1}\). Then the resistivity of the potentiometer wire is
If the maximum and minimum voltages of an A.M wave are \( V_{\max} \) and \( V_{\min} \) respectively, then the modulation factor ‘m’ is

Two long straight parallel conductors A and B carrying currents 4.5 A and 8 A respectively are separated by 25 cm in air. The resultant magnetic field at a point which is a distance of 15 cm from conductor A and 20 cm from conductor B is:

An alternating current is given by \( i = (3 \sin \omega t + 4 \cos \omega t) \) A. The rms current will be:
A superconductor exhibits:
A charged particle moving along a straight-line path enters a uniform magnetic field of \( 4 \) mT at right angles to the direction of the magnetic field. If the specific charge of the charged particle is \( 8 \times 10^7 \) C/kg, the angular velocity of the particle in the magnetic field is:

Three glass slabs A, B, C of different media are arranged as shown in the figure. Refractive index of B is 1.3 and the refractive index of C is 1.7. If the number of waves passing through B and C are equal to the total number of waves passing through B and C, then the refractive index of slab A is:

Three blocks of masses 2 m, 4 m and 6 m are placed as shown in figure. If \( \sin 37^\circ = \frac{3}{5} \), \( \sin 53^\circ = \frac{4}{5} \), the acceleration of the system is:

In case of diffraction, if \( a \) is a slit width and \( \lambda \) is the wavelength of the incident light, then the required condition for diffraction to take place is:
The gravitational potential energy of a body on the surface of the Earth is \(E\). If the body is taken from the surface of the Earth to a height equal to \(150%\) of the radius of the Earth, its gravitational potential energy is:

A wire of 60 cm length and mass 10 g is suspended by a pair of flexible leads in a magnetic field of 0.60 T as shown in the figure. The magnitude of the current required to remove the tension in the supporting leads is: 

A wire of length \(100 \text{ cm}\) and area of cross-section \(2 \text{ mm}^2\) is stretched by two forces of each \(440 \text{ N}\) applied at the ends of the wire in opposite directions along the length of the wire. If the elongation of the wire is \(2 \text{ mm}\), the Young’s modulus of the material of the wire is:
In a time of 2 s, the amplitude of a damped oscillator becomes \( \frac{1}{e} \) times its initial amplitude \( A \). In the next two seconds, the amplitude of the oscillator is:
A block of mass 100 g is attached to the end of a string of unknown material of 50 cm long and cross-sectional area of \(2 \, {cm}^2\). When the block is whirled horizontally at a constant angular speed of 40 m/s, it moves along a circular path of radius 52 cm. Young's modulus of the material is:
The mass of a particle is \( 1 \) kg and it is moving along the \( x \)-axis. The period of its oscillation is \( \frac{\pi}{2} \). Its potential energy at a displacement of \( 0.2 \) m is:
When 40 J of heat is absorbed by a monatomic gas, the increase in the internal energy of the gas is
A particle is projected from the surface of the Earth with a velocity equal to twice the escape velocity. When the particle is far from the Earth, its speed will be:

A unit positive charge is moved from point A to point B by a distance of 20 cm, on an equipotential surface as shown in the figure. The work done to move this charge is:

An object is placed at a distance of 18 cm in front of a mirror. If the image is formed at a distance of 4 cm on the other side, then the focal length, nature of the mirror and nature of the image are respectively:
Inner shell electrons in atoms moving from one energy level to another lower energy level produce:
At a place the horizontal component of earth’s magnetic field is \( 3 \times 10^{-5} \) T and the magnetic declination is \( 30^\circ \). A compass needle of magnetic moment \( 18 \) A\(m^2\) pointing towards geographic north at this place experiences a torque of:
Semiconductors suitable for solar cell fabrication have a band gap nearby:
Two parallel plate capacitors of capacitances 2 \(\mu F\) and 3 \(\mu F\) are joined in series and the combination is connected to a battery of V volts. The values of potential across the two capacitors \(V_1\) and \(V_2\) and energy stored in the two capacitors \(U_1\)and \(U_2\) respectively are related as_____
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