List of practice Questions

Each of the above three springs are identical (they have the same equilibrium length and spring constant $k$). They are fixed together as shown in the figure. What is the effective spring constant of the assembly?
Four forces, 5 N North, 6 N 20° S of E, 9 N 20°N of W and 10 N South, act on an object. The equilibrium force equals
The wavelength of the de-Broglie wave associated with a thermal neutron of mass $m$ at absolute temperature $T$ is given by (here, $K$ is the Boltzmann constant)
What are the units of the constant in the above equation?
Which of the following is true for an acid-base concentration cell such as the one used by the pH meter?
The momentum of a photon is $p$. The frequency associated with it is given by
A drop of liquid of density $\rho$ is floating half-immersed in a liquid of density $d$. If $\sigma$ is the surface tension, then the diameter of the drop of the liquid is
A ray of unpolarised light is incident on a glass plate at the polarising angle of $57^\circ$.
A transformer having efficiency of 90% is working on 200 V and 3 kW power supply. If the current in the secondary coil is 6 A the voltage across the secondary coil and the current in the primary coil respectively are
Consider a rotating spherical planet. The velocity of a point on its equator is $v$. The effect of rotation of the planet is to make $g$ at the equator $1/2$ of $g$ at the pole. What is the escape velocity for a polar particle on the planet expressed as a multiple of $v$?
Two conductors have the same resistance at 0°C but the temperature coefficients of resistance are $\alpha_1$ and $\alpha_2$. The respective temperature coefficients of their series and parallel combinations are nearly
Two identical wires A and B have the same length $L$ and carry the same current $I$. Wire A is bent into a circle of radius $R$ and wire B is bent to form a square of side $a$. If $B_1$ and $B_2$ are the values of magnetic induction at the centre of the square respectively, then the ratio $\frac{B_1{B_2}$ is}
A pendulum with a period of 2 seconds at sea level has its length doubled. Its new period is now most nearly:
A smooth inclined plane of length $L$ having inclination $\theta$ with the horizontal inside a lift which is moving down with retardation $\alpha$. The time taken by a body to slide down the inclined plane, from rest, will be:
A train accelerates from rest at a constant rate $\alpha$ for distance $X_1$ and time $t_1$. After that it retards to rest at constant rate $\beta$ for distance $X_2$ and time $t_2$. Then, it is found that
The time-period of a charged particle undergoing a circular motion in a uniform magnetic field is independent of its
Two charged spheres are separated by 2 mm. Which of the following would yield the greatest attractive force?
When a satellite is on the surface of a planet, it experiences a gravitational force $W$. What is the gravitational force when the satellite is at height $R/50$, where $R$ is the radius of the planet?
An air bubble starts rising from the bottom of a lake. Its diameter is 3.6 mm at the bottom and 4 mm at the surface. The depth of the lake is 250 cm and the temperature at surface is 40°C. What is the temperature at the bottom of the lake? Given atmospheric pressure = 76 cm of Hg and $g = 980 \, \text{cm/s^2$}
An ideal fluid with pressure $p$ flows through a horizontal pipe with radius $r$. If the radius of the pipe is increased by a factor of 2, which of the following most likely gives the new pressure?
Average energy in one time period of a simple harmonic oscillator whose amplitude is A, angular velocity $\omega$ and mass m, is:
Resistors $R_1$ and $R_2$ are placed in parallel as shown. If they have values of $5 \, \Omega$ and $10 \, \Omega$ respectively, their combined equivalent resistance is:
Resistors R1 and R2 are placed in parallel
The chemical potential energy in gasoline is converted to kinetic energy in cars. If a car accelerates from zero to 60 km/h, compared to the energy necessary to increase the velocity of the car from 30 to 60 km/h, the energy necessary to increase the velocity of the car from 30 to 60 km/h is:
Which of the following gives the percent change to the Young's modulus for a substance, when its cross-sectional area is increased by a factor of 3?
Different objects at different distances are seen by the eye. The parameter that remains constant is