List of top Physics Questions

equivalent resistance between ‘A’ and ‘B’

Consider a circuit where a cell of emf \( E_0 \) and internal resistance \( r \) is connected across the terminal A and B as shown in the figure. The value of \( R \) for which the power generated in the circuit is maximum, is given by:

When two objects are moving along a straight line in the same direction, the distance between them increases by 6 m in one second. If the objects move with their constant speed towards each other, the distance decreases by 8 m in one second. Then the speed of the objects are:

The total energy of a gas mixture of one mole of oxygen and 3 moles of argon at a temperature \( T \) by neglecting vibrational modes is:

If three sources of sound of frequencies \( (n-1), n, (n+1) \) are vibrated together, the number of beats produced and heard per second respectively are:

If the temperature of a gas is increased from \( 27^\circ C \) to \( 159^\circ C \), the increase in the rms speed of the gas molecules is:

If the length of a string is \(P\) when the tension in it is 6 N and its length is \(Q\) when the tension in it is 8 N, then the original length of the string is:

Two objects A and B are placed at 15 cm and 25 cm from the pole in front of a concave mirror having radius of curvature 40 cm. The distance between images formed by the mirror is:

Force between two point charges \( q_1 \) and \( q_2 \) placed in vacuum at a distance \( r \, \text{cm} \) apart is \( F \). Force between them when placed in a medium having dielectric \( K = 5 \) at \( r/5 \, \text{cm} \) apart will be:

If a freely falling body covers 80 m in the first 4 seconds, then in the next 4 seconds it covers a distance of:

Normally a capacitor is connected across the output terminals of a rectifier to

Water of mass \( m \) at \( 30^\circ C \) is mixed with \( 5 \) g of ice at \( -20^\circ C \). If the resultant temperature of the mixture is \( 6^\circ C \), then the value of \( m \) is: (Given: Specific heat capacity of ice = \( 0.5 \) cal \( g^{-1} \) \( ^\circ C^{-1} \), Specific heat capacity of water = \( 1 \) cal \( g^{-1} \) \( ^\circ C^{-1} \), Latent heat of fusion of ice = \( 80 \) cal \( g^{-1} \))

A body floats with \(\frac{1}{n}\) of its volume keeping outside of water. If the body has been taken to height \(h\) inside water and released, it will come to the surface after time \(t\). Then:

An alternating current having peak value 14.14 A is used to heat a metal wire. The value of the direct current \(i\) required to produce the same heating effect in the same wire is

A convex lens gives a virtual image when the object is placed on the principal axis

The maximum horizontal range of a ball projected from the ground is 32 m. If the ball is thrown with the same speed horizontally from the top of a tower of height 25 m, the maximum horizontal distance covered by the ball is: (Acceleration due to gravity \( g = 10 \, \text{m/s}^2 \)) \vspace{0.5cm}

A particle is moving along a circular track of radius 1 m with a uniform speed. The ratio of the distance covered and the displacement in half revolution is:

The electric field strength at a point in an electric field is 30 N/C. Find the force experienced by a charge of 20 C at that point.

100 gm of water at \( 60^\circ C \) is added to 180 gm of water at \( 95^\circ C \). The resultant temperature of the mixture is:

Magnetic flux of a 20-turn coil is reduced to zero from 0.3 weber in one second. Then the induced e.m.f between the terminals of the coil is:

Two unlike parallel forces of 2 N and 16 N act at the ends of a uniform rod of 21 cm length. The point where the resultant of these two forces acts at a distance of .............. from the greater force.

Two resistances combine in series order to provide 50 ohms resultant resistance, and when they combine in parallel order, they provide 8 ohms resultant resistance. Then the value of each resistance is:

A 60 kg man standing on a bridge, jumps vertically down onto a 540 kg boat moving in the river below him with a speed of 10 m/s. The change in the speed of the boat is: