List of top Physics Questions

A thin plano-convex lens of focal length 73.5 cm has a circular aperture of diameter 8.4 cm. If the refractive index of the material of the lens is \( \frac{5}{3} \), then the thickness of the lens is nearly.
The diameter of the objective of a telescope is 3.6 m. The limit of resolution of the telescope for a light of wavelength 540 nm is:
A resistor \( R \) dissipates power \( P \) when connected to a generator. If another resistor \( Q \) is put in series with \( R \), the power dissipated by \( R \) will:
Two metal spheres, one of radius $ \frac{R}{2} $ and the other of radius $ 2R $ respectively have the same surface charge density. They are brought in contact and separated. The ratio of their new surface charge densities is:
The electric charge on a body is always an integral multiple of 'e' where 'e' is the charge that an electron or proton carries. This concept is known as

Two charges $ -q $ each are fixed, separated by distance $ 2d $. A third charge $ q $ of mass $ m $ placed at the mid-point is displaced slightly by $ x' (x \ll d) $ perpendicular to the line joining the two fixed charges as shown in the figure. The time period of oscillation of $ q $ will be:

If 216 drops of the same size are charged at 200 V each and they combine to form a bigger drop, the potential of the bigger drop will be
The magnetic flux linked with a coil is given by the equation: $ \phi = 8t^2 + t + 10 $ The e.m.f. induced in the coil in the 3rd second will be

A charge \( Q \) is distributed over two concentric hollow spheres of radii \( r \) and \( R \) (\( R>r \)) such that their surface charge densities are equal. Find the electric potential at their common center.

Prove Mayer's relation: \( C_p - C_v = \frac{R}{J} \)

A resistor of resistance \( R \), inductor of inductive reactance \( 2R \) and a capacitor of capacitive reactance \( X_C \) are connected in series to an A.C. source. If the series LCR circuit is in resonance, then the power factor of the circuit and the value \( X_C \) are respectively:
The S.I. unit of electrical resistance is
Formula for specific resistance is
Calculate the resultant resistance in the following circuit.
resultant resistance
The resistance of a 10 m long wire is 10 $ \Omega $. Its length is increased by 25\% by stretching the wire uniformly. The new resistance is
A voltmeter of resistance $1000 \, \Omega $ and $0.5 \, \text{V/div} $ is to be converted into a voltmeter to make it read $1 \, \text{V/div} $. The value of high resistance to be connected in series with it is
If the unit of force and length are doubled, the unit of energy will be
You lift a heavy book from the floor of the room and keep it in the bookshelf having a height of 2m. This process takes 5 seconds. The work done by you will depend on
Energy a system possesses because of the force exerted on its mass by a gravitational or electromagnetic field with respect to a reference surface.
A scooter moves with a speed of 7 m/s on a straight road and is stopped by applying the brakes. Before stopping, the scooter travels 10 m. If the weight of the scooter is W, then the total resistance to the motion of the scooter will be
A block of mass 5 kg is placed on a rough horizontal surface with a coefficient of friction 0.5. If a horizontal force of 60 N is acting on it, then the acceleration of the block is (Acceleration due to gravity \( g = 10 \) ms\(^{-2}\)):

Find out the angle of refraction in a medium of refractive index \(\sqrt{3}\), when the angle of incidence is \(60^\circ\). 
 

Represent the variation of binding energy per nucleon with mass number. On the basis of it, explain the following: (i) Nuclear fission
(ii) Nuclear fusion
(iii) Nuclear energy
Obtain the formula of the relationship of drift velocity and potential difference.
In the diodes shown in the diagrams, which one is reverse biased?