List of top Physics Questions

A total of 48 J heat is given to one mole of helium kept in a cylinder. The temperature of helium increases by $2^\circ C$. The work done by the gas is: (Given, $R = 8.3 \, \text{J K}^{-1} \, \text{mol}^{-1}$).

Water boils in an electric kettle in 20 minutes after being switched on. Using the same main supply, the length of the heating element should be ………….. to …………. times of its initial length if the water is to be boiled in 15 minutes.

A sample of 1 mole gas at temperature T is adiabatically expanded to double its volume. If adiabatic constant for the gas is \(\gamma=\frac{3}{2}\) , then the work done by the gas in the process is:

A real gas within a closed chamber at \( 27^\circ \text{C} \) undergoes the cyclic process as shown in the figure. The gas obeys \( PV^3 = RT \) equation for the path \( A \) to \( B \). The net work done in the complete cycle is (assuming \( R = 8 \, \text{J/mol K} \)):

P-T diagram of an ideal gas having three different densities \( \rho_1, \rho_2, \rho_3 \) (in three different cases) is shown in the figure. Which of the following is correct:

The given figure represents two isobaric processes for the same mass of an ideal gas, then

A mixture of one mole of a monoatomic gas and one mole of a diatomic gas (rigid) are kept at room temperature (\(27^\circ \text{C}\)). The ratio of specific heat of gases at constant volume respectively is:

Two thermodynamical processes are shown in the figure. The molar heat capacity for process \( A \) and \( B \) are \( C_A \) and \( C_B \). The molar heat capacity at constant pressure and constant volume are represented by \( C_P \) and \( C_V \), respectively. Choose the correct statement.

A gas mixture consists of 8 moles of argon and 6 moles of oxygen at temperature T. Neglecting all vibrational modes, the total internal energy of the system is

A diatomic gas (\( \gamma = 1.4 \)) does 100 J of work in an isobaric expansion. The heat given to the gas is:

At room temperature \( 27^\circ\text{C} ,\) the resistance of a heating element is \(50 \, \Omega\). The temperature coefficient of the material is \(2.4 \times 10^{-4}\)  \(^\circ\text{C}^{-1} \). The temperature of the element, when its resistance is \(62 \, \Omega\) , is _________\(\degree C\).

During an adiabatic process, the pressure of a gas is found to be proportional to the cube of its absolute temperature. The ratio of \(\frac{C_p}{C_v}\) for the gas is :

The equivalent resistance between A and B is:

In the given figure \( R_1 = 10 \, \Omega \), \( R_2 = 8 \, \Omega \), \( R_3 = 4 \, \Omega \), and \( R_4 = 8 \, \Omega \). The battery is ideal with an EMF of 12V.
The equivalent resistance of the circuit and the current supplied by the battery are respectively:

Twelve wires, each having resistance \( 2 \, \Omega \), are joined to form a cube. A battery of \( 6 \, \text{V} \) emf is joined across points \( a \) and \( c \). The voltage difference between \( e \) and \( f \) is ______ \( \text{V} \).

The current flowing through the 1\(\Omega \) resistor is \(\frac{n}{10}\)A. The value of n is ________.

In the given circuit, the current flowing through the resistance \( 20 \Omega \) is \( 0.3 \, \text{A} \), while the ammeter reads \( 0.9 \, \text{A} \). The value of \( R_1 \) is ______ \( \Omega \).

A wire of length 10 cm and radius \( \sqrt{7} \times 10^{-4} \, m \) is connected across the right gap of a meter bridge. When a resistance of 4.5 \( \Omega \) is connected on the left gap by using a resistance box, the balance length is found to be at 60 cm from the left end. If the resistivity of the wire is \( R \times 10^{-7} \, \Omega \, m \), then the value of \( R \) is:

The value of net resistance of the network as shown in the given figure is :

The equivalent resistance of the following network is _____ \( \Omega \).

In the experiment to determine the galvanometer resistance by half-deflection method, the plot of \(\frac{1}{ \theta}\) vs the resistance (R) of the resistance box is shown in the figure. The figure of merit of the galvanometer is .............. ×10^–1 A/division. [The source has emf 2V]

A potential divider circuit is shown in figure. The output voltage V₀ is

Two conductors have the same resistances at \( 0^\circ \text{C} \) but their temperature coefficients of resistance are \( \alpha_1 \) and \( \alpha_2 \). The respective temperature coefficients for their series and parallel combinations are:

Wheatstone bridge principle is used to measure the specific resistance \( (S_1) \) of a given wire, having length \( L \), radius \( r \). If \( X \) is the resistance of the wire, then specific resistance is: $$ S_1 = X\left( \frac{\pi r^2}{L} \right). $$ If the length of the wire gets doubled, then the value of specific resistance will be: 

A heater is designed to operate with a power of 1000 W in a 100 V line. It is connected in combination with a resistance of 10 \(\Omega\) and a resistance \(R\), to a 100 V mains as shown in the figure. For the heater to operate at 62.5 W, the value of \(R\) should be \(\dots\) \(\Omega\).