List of top Physics Questions

In the circuit, three ideal cells of e.m.f. $ V $, $ V $, and $ 2V $ are connected to a resistor of resistance $ R $, a capacitor of capacitance $ C $, and another resistor of resistance $ 2R $ as shown in the figure. In the steady state, find (i) the potential difference between P and Q, (ii) the potential difference across capacitor C.

The distance of an object from the first focal point of a biconvex lens is $ X_1 $ and distance of the image from second focal point is $ X_2 $. The focal length of the lens is:

The electric field at a point in a region is given by $ \vec{E} = \alpha \frac{\hat{r}}{r^3} $, where $ \alpha $ is a constant and $ r $ is the distance of the point from the origin. The magnitude of potential of the point is:

Two cities X and Y are connected by a regular bus service with a bus leaving in either direction every T min. A girl is driving scooty with a speed of 60 km/h in the direction X to Y. She notices that a bus goes past her every 30 minutes in the direction of her motion, and every 10 minutes in the opposite direction. Choose the correct option for the period T of the bus service and the speed (assumed constant) of the buses.

An electric dipole of dipole moment $ \vec{p} = (0.8\,\hat{i} + 0.6\,\hat{j}) \times 10^{-29}\,\text{Cm} $ is placed in an electric field $ \vec{E} = 1.0 \times 10^7\,\hat{k}\,\text{V/m} $. Calculate the magnitude of the torque acting on it and the angle it makes with the x-axis, at this instant.

A compound microscope has an objective and an eyepiece of focal lengths $ f_0 $ and $ f_e $, respectively. To obtain a large magnification of a small object, the microscope should have:

A parallel plate capacitor has plate area $ A $ and plate separation $ d $. Half of the space between the plates is filled with a material of dielectric constant $ K $ in two ways as shown in the figure. Find the values of the capacitance of the capacitors in the two cases.

A current-carrying coil is placed in an external uniform magnetic field. The coil is free to turn in the magnetic field. What is the net force acting on the coil? Obtain the orientation of the coil in stable equilibrium. Show that in this orientation the flux of the total field (field produced by the loop + external field) through the coil is maximum.

A body of mass 2 kg is moving in a circular path of radius 3 m with a constant speed of 6 m/s. What is the centripetal force acting on the body?

A ray of light is incident on a refracting face AB of a prism ABC at an angle of $ 45^\circ $. The ray emerges from face AC and the angle of deviation is $ 15^\circ $. The angle of prism is $ 30^\circ $. Show that the emergent ray is normal to the face AC from which it emerges out. Find the refraction index of the material of the prism.

Figure shows the graph of angle of deviation $ \delta $ versus angle of incidence $ i $ for a light ray striking a prism. The prism angle is

angle of deviation δ versus angle of incidence i

A 200 g sample of water at 80°C is mixed with 100 g of water at 20°C. Assuming no heat loss to the surroundings, what is the final temperature of the mixture?

(I) Write Ampere’s circuital law in mathematical form and explain the terms used.
(II) As the current-carrying solenoid is made longer, the magnetic field produced outside it approaches zero. Why?
(III) A flexible loop of irregular shape carrying current, when located in an external magnetic field, changes to a circular shape. Give reason.

The effective resistance between points A and B in the given circuit is:

Which of the following is an electrical conductor at room temperature?

Two cells of emf 10 V each, two resistors of 20 $ \Omega $ and 10 $ \Omega $, and a bulb B of 10 $ \Omega $ resistance are connected together as shown in the figure. Find the current that flows through the bulb.

A body of mass 10 kg is at a height of 5 m above the surface of the Earth. What is the gravitational potential energy of the body? (Take $ g = 10 \, \text{m/s}^2 $)

A concave mirror has a focal length of 20 cm. An object is placed 60 cm in front of the mirror. Find the image distance.

Two conductors A and B of the same material have their lengths in the ratio 1:2 and radii in the ratio 2:3. If they are connected in parallel across a battery, the ratio $ \frac{v_A}{v_B} $ of the drift velocities of electrons in them will be:

At a height $ h $ above the Earth's surface, the acceleration due to gravity becomes $ \frac{g}{\sqrt{3}} $. What is the value of $ h $ in terms of the Earth's radius $ R $?

A body of mass $ 1.5 \, \text{kg} $ is dropped from a height of $ 20 \, \text{m} $. What is its speed just before hitting the ground? (Assume $ g = 9.8 \, \text{m/s}^2 $)

A physical quantity P is related to four observations a, b, c, and d as follows: P = a³ b² (c / √d) The percentage errors of measurement in a, b, c, and d are 1%, 3%, 2%, and 4% respectively. The percentage error in the quantity P is:

Estimate the ratio of shortest wavelength of radio waves to the longest wavelength of gamma waves.

A conducting bar moves on two conducting rails as shown in the figure. A constant magnetic field $ B $ exists into the page. The bar starts to move from the vertex at time $ t = 0 $ with a constant velocity. If the induced EMF is $ E \propto t^n $, then the value of $ n $ is _____.

In the figure, curved lines represent equipotential surfaces. A charge $ Q $ is moved along different paths A, B, C, and D. The work done on the charge will be maximum along the path: