Question Bank Directory

The two nearest harmonics of a tube closed at one end and open at the other end are $220 \text{ Hz}$ and $260 \text{ Hz}$. What is the fundamental frequency of the system?

A monoatomic gas at pressure $p_1$ and volume $V_1$ is compressed adiabatically to $\frac{1}{8}^{\text{th}}$ its original volume. What is the final pressure of the gas?

Four-point +ve charges of the same magnitude (Q) are placed at four corners of a rigid square frame as shown in the figure. The plane of the frame is perpendicular to Z-axis. If a –ve point charge is placed at a distance z away from the above frame (z<<L) then

An electron having charge e and mass m is moving in a uniform electric field E. Its acceleration will be:

A wave travelling in the positive x-direction having maximum displacement along y-direction as $1 \text{ m}$, wavelength $2\pi \text{ m}$ and frequency of $1/\pi \text{ Hz}$ is represented by

The electric intensity due to an infinite cylinder of radius $R$ and having charge $q$ per unit length at a distance $r$ ($r > R$) from its axis is:

A wire loop is rotated in a magnetic field. The frequency of change of direction of the induced emf is:

An electron moves on a straight-line path XY as shown. The abcd is a coil adjacent to the path of the electron. What will be the direction of the current, if any, induced in the coil?

Shown below is a distribution of charges. The flux of electric field due to these charges through the surface S is:

The second overtone of an open organ pipe has the same frequency as the first overtone of a closed pipe $L$ metre long. The length of the open pipe will be

An ideal gas undergoes four different processes from the same initial state as shown in the figure below. Those processes are adiabatic, isothermal, isobaric, and isochoric. The curve which represents the adiabatic process among $1$, $2$, $3$ and $4$ is:

The magnetic flux linked with a coil (in Wb) is given by the equation $\phi = 5t^2 + 3t + 60$. The magnitude of induced emf in the coil at $t = 4$ s will be:

An air column, closed at one end and open at the other, resonates with a tuning fork when the smallest length of the column is $50 \text{ cm}$. The next larger length of the column resonating with the same tuning fork is

Sound waves travel at $350 \text{ m/s}$ through warm air and at $3500 \text{ m/s}$ through brass. The wavelength of a $700 \text{ Hz}$ acoustic wave as it enters brass from warm air:

A coil of resistance $400\Omega$ is placed in a magnetic field. If the magnetic flux $\phi\;(\text{Wb})$ linked with the coil varies with time $t\;(\text{sec})$ as $\phi=50t^2+4$. The current in the coil at $t=2\text{s}$ is:

A conducting circular loop is placed in a uniform magnetic field $0.04\text{ T}$ with its plane perpendicular to the magnetic field. The radius of the loop starts shrinking at $2\text{ mm/s}$. The induced emf in the loop when the radius is $2\text{ cm}$ is:

If we study the vibration of a pipe open at both ends, then the following statement is not true:

A wooden stick of length $3l$ is rotated about an end with constant angular velocity $\omega$ in a uniform magnetic field $B$ perpendicular to the plane of motion. If the upper one third of its length is coated with copper, the potential difference across the whole length of the stick is:

An ideal gas goes from state $A$ to state $B$ via three different processes, as indicated in the $P$-$V$ diagram. If $Q_1, Q_2, Q_3$ indicates the heat absorbed by the gas along the three processes and $\Delta U_1, \Delta U_2, \Delta U_3$ indicates the change in internal energy along the three processes respectively, then:

A uniform rope of length $L$ and mass $m_1$ hangs vertically from a rigid support. A block of mass $m_2$ is attached to the free end of the rope. A transverse pulse of wavelength $\lambda_1$ is produced at the lower end of the rope. The wavelength of the pulse when it reaches the top of the rope is $\lambda_2$. The ratio $\frac{\lambda_2}{\lambda_1}$ is: