List of top Physics Questions

The magnitudes of power of a biconvex lens (refractive index \(1.5\)) and that of a plano-convex lens (refractive index \(1.7\)) are same. If the curvature of the plano-convex lens exactly matches with the curvature of the back surface of the biconvex lens, then the ratio of radii of curvature of the front and back surfaces of the biconvex lens is:

In the following \(p\text{–}V\) diagram, the equation of state along the curved path is given by \[ (V-2)^2 = 4ap, \] where \(a\) is a constant. The total work done in the closed path is: 

A convex lens of refractive index \(1.5\) and focal length \(f=18\) cm is immersed in water. The difference in focal lengths of the given lens when it is in water and in air is \( \alpha \times f \). Find the value of \( \alpha \). (Given: refractive index of water \(=\dfrac{4}{3}\))

The equivalent resistance between the points \(A\) and \(B\) in the given circuit is \[ \frac{x}{5}\,\Omega. \] Find the value of \(x\).

In the potentiometer, when the cell in the secondary circuit is shunted with \(4\,\Omega\) resistance, the balance is obtained at a length \(120\) cm of wire. Now when the same cell is shunted with \(12\,\Omega\) resistance, the balance is shifted to a length of \(180\) cm. The internal resistance of the cell is ________ \( \Omega \).
Given below are two statements: Statement I: A plane wave after passing through a prism remains a plane wave, but passing through a small pin hole may become a spherical wave. Statement II: The curvature of a spherical wave emerging from a slit will increase for increasing slit width. In the light of the above statements, choose the correct answer:
A cubical block of density \( \rho_b = 600\,\text{kg/m}^3 \) floats in a liquid of density \( \rho_l = 900\,\text{kg/m}^3 \). If the height of block is \(H = 8.0\,\text{cm}\), then height of the submerged part is ________ cm.
A point source is kept at the center of a spherically enclosed detector. If the volume of the detector is increased by 8 times, the intensity will
Distance between an object and three times magnified real image is 40 cm. The focal length of the mirror used is ________ cm.
When a light of a given wavelength falls on a metallic surface the stopping potential for photoelectrons is \(3.2\ \text{V}\). If a second light having wavelength twice of the first light is used, the stopping potential drops to \(0.7\ \text{V}\). The wavelength of the first light is ________ m.
The reading of the ammeter (\(A\)) in steady state in the following circuit (assuming negligible internal resistance of the ammeter) is ________ A.

The velocity (\(v\)) – distance (\(x\)) graph is shown in the figure. Which graph represents acceleration (\(a\)) versus distance (\(x\)) variation of this system? 

Two identical circular loops \(P\) and \(Q\) each of radius \(r\) are lying in parallel planes such that they have common axis. The current through \(P\) and \(Q\) are \(I\) and \(4I\) respectively in clockwise direction as seen from \(O\). The net magnetic field at \(O\) is: 

Identify the correct truth table of the given logic circuit. 

In the Young's double slit experiment the intensity produced by each one of the individual slits is \(I_0\). The distance between two slits is \(2\,\text{mm}\). The distance of screen from slits is \(10\,\text{m}\). The wavelength of light is \(6000\,\text{\AA}\). The intensity of light on the screen in front of one of the slits is ________.
A moving coil galvanometer of resistance \(100\,\Omega\) shows a full scale deflection for a current of \(1\,\text{mA}\). The value of resistance required to convert this galvanometer into an ammeter, showing full scale deflection for a current of \(5\,\text{mA}\), is ________ \(\Omega\).
Five persons \(P_1, P_2, P_3, P_4\) and \(P_5\) recorded object distance (\(u\)) and image distance (\(v\)) using same convex lens having power \(+5\) D as (25,96), (30,62), (35,37), (45,35) and (50,32) respectively. Identify correct statement.
The fifth harmonic of a closed organ pipe is found to be in unison with the first harmonic of an open pipe. The ratio of lengths of closed pipe to that of the open pipe is \( \frac{5}{x} \). The value of \( x \) is ________.
When 300 J of heat is given to an ideal gas with \( C_p = \frac{7}{2}R \), its temperature rises from 20°C to 50°C keeping its volume constant. The mass of the gas is (approximately) ______ g. (R = 8.314 J/mol K)
A flexible chain of mass \(m\) hangs between two fixed points at the same level. The inclination of the chain with the horizontal at the two points of support is \(30^\circ\). Considering the equilibrium of each half of the chain, the tension of the chain at the lowest point is ________.
In a meter bridge experiment to determine the value of unknown resistance, first the resistances \(2\,\Omega\) and \(3\,\Omega\) are connected in the left and right gaps of the bridge and the null point is obtained at a distance \(l\) cm from the left end. Now, when an unknown resistance \(x\,\Omega\) is connected in parallel to \(3\,\Omega\), the null point is shifted by \(10\,\text{cm}\) to the right. The value of \(x\) is ________ \(\Omega\).
In a vernier callipers, 50 vernier scale divisions are equal to 48 main scale divisions. If one main scale division = 0.05 mm, then the least count of the vernier callipers is ________ mm.
The binding energy for the following nuclear reactions are expressed in MeV.
\[ {}^{3}_{2}\text{He} + {}^{1}_{0}\text{n} \rightarrow {}^{4}_{2}\text{He} + 20 \text{ MeV} \] \[ {}^{4}_{2}\text{He} + {}^{1}_{0}\text{n} \rightarrow {}^{5}_{2}\text{He} - 0.9 \text{ MeV} \] If \( X_3, X_4, X_5 \) denote the stability of \( {}^{3}_{2}\text{He}, {}^{4}_{2}\text{He} \) and \( {}^{5}_{2}\text{He} \), respectively, then the correct order is:
A soap bubble of surface tension \(0.04\,\text{N/m}\) is blown to a diameter of \(7\,\text{cm}\). If \((15000 - x)\,\mu\text{J}\) of work is done in blowing it further to make its diameter \(14\,\text{cm}\) \((\pi = 22/7)\), then the value of \(x\) is ________.

A point charge \(q = 1\,\mu\text{C}\) is located at a distance \(2\,\text{cm}\) from one end of a thin insulating wire of length \(10\,\text{cm}\) having a charge \(Q = 24\,\mu\text{C}\), distributed uniformly along its length, as shown in the figure. Force between \(q\) and wire is ________ N.