List of top Physics Questions

A car is moving on a horizontal curved road with radius 50 m. The approximate maximum speed of the car will be, if the friction coefficient between tyres and road is 0.34. (Take g = 10 m/s²):

Which of the following statements is not correct in the case of light emitting diodes (LEDs)?
A. It is a heavily doped p-n junction.
B. It emits light only when it is forward-biased.
C. It emits light only when it is reverse-biased.
D. The energy of the light emitted is equal to or slightly less then the energy gap of the semiconductor used.
Choose the correct answer from the options given below:

In a Young’s double slit experiment, two slits are illuminated with light of wavelength \(800 \, \text{nm}\). The first minimum is detected at \(P\). The value of slit separation \(a\) is:

If a radioactive element with a half-life of 30 min undergoes beta decay. The fraction of the radioactive element that remains undecayed after 90 min is:

A single current-carrying loop of wire carrying current I flows in the anticlockwise direction (seen from the +z direction) and lies in the xy plane. The plot of \(\hat{j}\) component of magnetic field (\(B_y\)) at a distance a (less than radius of the coil) and on the yz plane vs z coordinate looks like:

Two particles of equal mass ‘m’ move in a circle of radius ‘r’ under the action of their mutual gravitational attraction. The speed of each particle will be :

Find the mutual inductance in the arrangement, when a small circular loop of radius R is placed inside a large square loop of side \(L\) (\(L \gg R\)). The loops are coplanar and their centers coincide:

A person observes two moving trains, ‘A’ reaching the station and ‘B’ leaving the station with equal speed of 30 m/s. If both trains emit sounds with frequency 300 Hz, (Speed of sound: 330 m/s) approximate difference of frequencies heard by the person will be:

Ratio of thermal energy released in two resistors R and 3R connected in parallel in an electric circuit is:

A block of mass m slides down the plane inclined at angle \(30\degree\) with an acceleration \(\frac{g}{4}\). The value of the coefficient of kinetic friction will be:

The threshold wavelength for photoelectric emission from a material is \(5500Å\). Photoelectrons will be emitted, when this material is illuminated with monochromatic radiation from a
A. 75 W infra-red lamp
B. 10 W infra-red lamp
C. 75 W ultra-violet lamp
D. 10 W ultra-violet lamp
Choose the correct answer from the options given below:

Which of the following are true?
A. Speed of light in vacuum is dependent on the direction of propagation.
B. Speed of light in a medium is independent of the wavelength of light.
C. The speed of light is independent of the motion of the source.
D. The speed of light in a medium is independent of intensity.
Choose the correct answer from the options given below:

If the height of transmitting and receiving antennas are 80 m each, the maximum line of sight distance will be:
Given: Earth’s radius = \(6.4 \times 106\text{ m}\)

The surface tension of a soap bubble is \(2 \times 10^{-2} \, \text{N/m}\). Work done to increase the radius of the bubble from 3.5 cm to 7 cm will be:

A bicycle tyre is filled with air having pressure of 270 kPa at \(27\degree C\). The approximate pressure of the air in the tyre when the temperature increases to \(36\degree C\) is:

The magnitude of magnetic induction at the mid-point O due to the current arrangement shown in the figure is:

Match List I with List II:

List-I (Physical Quantity)		List-II (Dimensional Formula)
(A)	Pressure Gradient	(I)	\([M^0L^2T^{–2}]\)
(B)	Energy density	(II)	\([M^1L^{–1}T^{–2}]\)
(C)	Electric field	(III)	\([M^1L^{–2}T^{–2}]\)
(D)	Latent heat	(IV)	\([M^1L^1T^{–3}A^{–1}]\)

Choose the correct answer from the options given below:

In a cuboid of dimension \(2L \times 2L \times L\), a charge q is placed at the center of the surface ‘S’ having area of 4 L². The flux through the opposite surface to ‘S’ is:

A stone is projected at an angle of \(30\degree\) to the horizontal. The ratio of kinetic energy at projection to its kinetic energy at the highest point is:

A solid sphere of mass 2 kg is making pure rolling on a horizontal surface with kinetic energy 2240 J. The velocity of centre of mass of the sphere will be ____ ms^–1.

A small ball of mass M and density \(\rho\) is dropped in a viscous liquid of density \(\rho_0\). After some time, the ball falls with a constant velocity. What is the viscous force on the ball ?

The resistivity (\(\rho\)) of semiconductor varies with temperature. Which of the following curve represents the correct behavior

A point charge \(q_1 = 4q_0\) is placed at origin. Another point charge \(q_2 = –q_0\) is placed at \(x = 12\text{ cm}\). Charge of proton is q₀. The proton is placed on x axis so that the electrostatic force on the proton is zero. In this situation, the position of the proton from the origin is _____ cm.

A tennis ball is dropped on to the floor from a height of 9.8 m. It rebounds to a height 5.0 m. Ball comes in contact with the floor for 0.2 s. The average acceleration during contact is_____ m/s². (Given g =10 m/s²)

A certain elastic conducting material is stretched into a circular loop. It is placed with its plane perpendicular to a uniform magnetic field B = 0.8 T. When released the radius of the loop starts shrinking at a constant rate of 2 cm/s. The induced emf in the loop at an instant when the radius of the loop is 10 cm will be _____ mV.