List of practice Questions

Two wires of the same material (Young’s modulus \( Y \)) and same length \( L \) but radii \( R \) and \( 2R \) respectively, are joined end to end and a weight \( W \) is suspended from the combination. The elastic potential energy in the system is: 


 

With rise in temperature, the Young's modulus of elasticity:
Young’s modulus of a material is \( Y \). If the length of a wire is doubled and the cross-sectional area is halved, then Young’s modulus will be:
Pressure inside two soap bubbles are 1.01 and 1.02 atmosphere, respectively. The ratio of their volumes is:

A cube of ice floats partly in water and partly in kerosene oil. The ratio of volume immersed in water to that in kerosene oil is: 
 

A solid metallic cube having total surface area \( 24 \, m^2 \) is uniformly heated. If its temperature is increased by \( 10^\circ C \), calculate the increase in volume of the cube.
Given: \( \alpha = 5.0 \times 10^{-4} \, C^{-1} \)

A gas can be taken from A to B via two different processes ACB and ADB. When path ACB is used, \( 60 J \) of heat flows into the system and \( 30 J \) of work is done by the system. If path ADB is used, the work done by the system is \( 10 J \). The heat flow into the system in path ADB is: 
 

On Celsius scale, the temperature of a body increases by \( 40^\circ C \). The increase in temperature on Fahrenheit scale is:
The temperature of an ideal gas is increased from 200 K to 800 K. If the RMS speed of gas at 200 K is \( v_0 \), then the RMS speed of the gas at 800 K will be:
Water flows from a tap of diameter 1.5 cm with velocity \( 7.5 \times 10^{-5} \, \text{m}^{3}\text{s}^{-1} \). The coefficient of viscosity of water is \( 10^{-3} \) Pas. The flow is:
Two vessels A and B are of the same size and are at the same temperature. A contains 1 g of hydrogen and B contains 1 g of oxygen. \( P_A \) and \( P_B \) are the pressures of the gases in A and B respectively, then \( \frac{P_A}{P_B} \) is:
A particle executes simple harmonic motion between \( x = -A \) and \( x = +A \). If the time taken by the particle to go from \( x = 0 \) to \( \frac{A}{2} \) is 2 s, then the time taken by the particle in going from \( x = \frac{A}{2} \) to \( A \) is:
The speed of sound in oxygen at STP will be approximately:(Given, R = 8.3J\((K)^−1\), \(γ = 1.4)\)

A plane progressive wave is given by y = 2 cos 2pi (330t - x) m. The frequency of the wave is:} 
 

An oil drop of radius \(1 \, \mu{m}\) is held stationary under a constant electric field of \(3.65 \times 10^4 \, {N/C}\) due to some excess electrons present on it. If the density of the oil drop is \(1.26 \, {g/cm}^3\), then the number of excess electrons on the oil drop approximately is:
[Take, g = 10 m/s2]
The potential of a large liquid drop when eight liquid drops are combined is 20 V. Then, the potential of each single drop was:
The electric field at point (30, 30, 0) due to a charge of \(0.008 \, \mu{C}\) placed at the origin will be: (coordinates are in cm)
If two charges \( q_1 \) and \( q_2 \) are separated with distance 'd' and placed in a medium of dielectric constant K. What will be the equivalent distance between charges in air for the same electrostatic force?
Electric potential at a point 'P' due to a point charge of \( 5 \times 10^{-9} \) C is 50 V. The distance of 'P' from the point charge is: (Assume, \( \frac{1}{4\pi\epsilon_0} = 9 \times 10^{9} \, {Nm}^2{C}^{-2} \))

Five charges +q, +5q, -2q, +3q and -4q are situated as shown in the figure. The electric flux due to this configuration through the surface S is: 
 

A parallel plate capacitor with plate area \(A\) and plate separation \(d = 2\) m has a capacitance of \(4\mu F\). The new capacitance of the system if half of the space between them is filled with a dielectric material of dielectric constant \(K = 3\) (as shown in the figure) will be: 
 


 

In the following circuit diagram, when the \(3\Omega\) resistor is removed, the equivalent resistance of the network: 
 

Raju, Sohan, and Tina are partners in a firm sharing profits and losses in the ratio of 2 : 2 : 1. Tina is guaranteed a minimum amount of ₹40,000 as a share of profit every year. Any deficiency arising on that account shall be borne by Raju. If profit of the firm for the year ended 31st March, 2023 is ₹1,60,000, Raju will bear a deficiency of:
 

A wire of resistance \(160\Omega\) is melted and drawn into a wire of one-fourth of its length. The new resistance of the wire will be:
Five cells each of emf \(E\) and internal resistance \(r\) send the same amount of current through an external resistance \(R\) whether the cells are connected in parallel or in series. Then the ratio \(\frac{R}{r}\) is: