List of top Physics Questions

The unit of thermal conductivity is:

The radius of circle, the period of revolution, initial position and sense of revolution are indicated in the fig.

y- projection of the radius vector of rotating particle P is:

A cylindrical conductor of radius R is carrying a constant current. The plot of the magnitude of the magnetic field, B with the distance, d, from the centre of the conductor, is correctly represented by the figure :

A parallel plate capacitor of capacitance \(20 μF\) is being charged by a voltage source whose potential is changing at the rate of \(3 V/s.\) The conduction current through the connecting wires, and the displacement current through the plates of the capacitor, would be, respectively:

Two parallel infinite line charges with linear charge densities \(+λ \frac Cm\) and \(-λ \frac Cm\) are placed at a distance of \(2R\) in free space. What is the electric field mid-way between the two line charges

In which of the following devices, the eddy current effect is not used?

At a point A on the earth's surface the angle of dip, \(\delta=+25°\). At a point B on the earth's surface the angle of dip, \(\delta=-25°\). We can interpret that: 

A 800 turn coil of effective area \(0.05\ m^2\) is kept perpendicular to a magnetic field \( 5 \times 10^{-5} T.\) When the plane of the coil is rotated by \(90\degree\) around any of its coplanar axis in \(0.1 s\), the emf induced in the coil will be:

Ionized hydrogen atoms and a-particles with same momenta enters perpendicular to a constant magnetic field, B. The ratio of their radii of their paths \( r_H: r_\alpha\) will be:

Two particles \(A\) and \(B\) are moving in uniform circular motion in concentric circles of radii \(ra\) and \(rb\) with speed \(\upsilon_A\)and \(\upsilon_B\)respectively. Their time period of rotation is the same. The ratio of angular speed of \(A\) to that of \(B \)will be: 

Body A of mass 4m moving with speed u collides with another body B of mass 2m, at rest. The collision is head on and elastic in nature. After the collision the fraction of energy lost by the colliding body A is:

The displacement of a particle executing simple harmonic motion is given by \(y=A_0+A sin\omega t+Bcos\omega t.\) Then the amplitude of its oscillation is given by:

The speed of a swimmer in still water is \(20 m/s\). The speed of river water is \(10 m/s\) and is flowing due east. If he is standing on the south bank and wishes to cross the river along the shortest path, the angle at which he should make his strokes w.r.t. north is given by:

Increase in temperature of a gas filled in a container would lead to:

A hollow metal sphere of radius R is uniformly charged. The electric field due to the sphere at a distance r from the centre :

When an object is shot from the bottom of a long smooth inclined plane kept at an angle \(60 \degree\)with horizontal, it can travel a distance \(x_1\) along the plane. But when the inclination is decreased to \(30 \degree\) and the same object is shot with the same velocity, it can travel \(x_2\) distance. Then \(x_1:x_2\) will be:

The correct Boolean operation represented by the circuit diagram drawn is :

Which of the following acts as a circuit protection device?

Average velocity of a particle executing SHM in one complete vibration is:

The earth?s mass is $ 80 $ times that of moon and their diameters are $ 1600 \,km $ and $ 800 \,km $ , respectively. If $ g $ is the value of acceleration due to gravity on earth, what is its value on moon?

The refractive index of glass with respect to air is 2. The critical angle at their interface i

If 'a' is the thickness of the glass slab and 'b' is the vertical shift of an object through it, then refractive index of the glass slab is

When we sit at a camp fire, objects beyond the fire are seen swaying. The principle involved in it is

The magnification of an object of height 1 m using a spherical mirror is 1.5. The size of the image is

Which among the following is not a physical quantity?