List of top Physics Questions

A convex lens has power \( P \). It is cut into two halves along its principal axis. Further, one piece (out of two halves) is cut into two halves perpendicular to the principal axis as shown in the figure. Choose the incorrect option for the reported lens pieces.

A gas is taken from state A to state B along two different paths 1 and 2. The heat absorbed and work done by the system along these two paths are \( Q_1 \) and \( W_1 \), and \( Q_2 \) and \( W_2 \), respectively. Then

In determining the refractive index of a glass slab using a travelling microscope, the following readings are tabulated:
(a) Reading of travelling microscope for ink = 8.123 cm
(b) Reading of travelling microscope for ink through glass slab = 6.123 cm
(c) Reading of travelling microscope for chalk dust on glass slab = 8.123 cm
From the data, the refractive index of a glass slab is:}

In domestic electric mains supply, the voltage and the current are

A particle is in uniform circular motion. The equation of its trajectory is given by \( x = 2t^2 - 3t + 5 \), where \( x \) and \( y \) are in meters. The speed of the particle is 2 m/s. When the particle attains the lowest \( y \)-coordinate, the acceleration of the particle is (in \( \text{m/s}^2 \)):

In the projectile motion of a particle on a level ground, which of the following remains constant with reference to time and position?

A block of certain mass is placed on a rough floor. The coefficients of static and kinetic friction between the block and the floor are 0.4 and 0.25 respectively. A constant horizontal force \( F = 20 \, \text{N} \) acts on it so that the velocity of the block varies with time according to the following graph. The mass of the block is nearly (Take \( g = 10 \, \text{m/s}^2 \)):

If \( r_1, v_1, L_1 \) and \( r_2, v_2, L_2 \) are radii, velocities, and angular momenta of a planet at perihelion and aphelion of its elliptical orbit around the Sun respectively, then

Which of the following statements is correct for an n-type semiconductor?

A wooden block of mass M lies on a rough floor. Another wooden block of the same mass is hanging from the point O through strings as shown in the figure. To achieve equilibrium, the coefficient of static friction between the block on the floor and the floor itself is

Which of the following expressions can be deduced on the basis of dimensional analysis? (All symbols have their usual meanings)

The image formed by an objective lens of a compound microscope is

Two cells of emf \( E_1 \) and \( E_2 \), and internal resistances \( r_1 \) and \( r_2 \), respectively, are connected in parallel as shown in the figure. The equivalent emf of the combination is \( E_{\text{eq}} \). Then

A horizontal pipe carries water in a streamlined flow. At a point along the pipe, where the cross-sectional area is \( 10 \, \text{cm}^2 \), the velocity of water is 1 m/s and the pressure is 2000 Pa. What is the pressure of water at another point where the cross-sectional area is \( 5 \, \text{cm}^2 \)? [Density of water = 1000 kg/mÂ³]

Two wires A and B are made of the same material. Their diameters are in the ratio 1:2 and lengths are in the ratio 1:3. If they are stretched by the same force, then increase in their lengths will be in the ratio of

When a bar magnet is pushed towards the coil, along its axis, as shown in the figure, the galvanometer pointer deflects towards X. When this magnet is pulled away from the coil, the galvanometer pointer

The anode voltage of a photocell is kept fixed. The frequency of the light falling on the cathode is gradually increased. Then the correct graph which shows the variation of photo current \( I \) with the frequency \( f \) of incident light is

Three metal rods of the same material and identical in all respects are joined as shown in the figure. The temperatures at the ends of these rods are maintained as indicated. Assuming no heat energy loss occurs through the curved surfaces of the rods, the temperature at the junction is

At 27Â°C temperature, the mean kinetic energy of the atoms of an ideal gas is \( E_1 \). If the temperature is increased to 327Â°C, then the mean kinetic energy of the atoms will be

A ray of light passes from vacuum into a medium of refractive index \( n \). If the angle of incidence is twice the angle of refraction, then the angle of incidence in terms of refractive index \( n \) is