List of top Physics Questions

A beam of incident parallel light falls on a diverging lens of focal length \(20\) cm in magnitude. If a converging lens of focal length \(15\) cm in magnitude is placed at a distance of \(10\) cm to the right of the diverging lens on the other side, then, the final image formed is:

A rectangular coil of 250 turns has an average area of \( 20 \, cm \times 15 \, cm \). The coil rotates with a speed of 60 cycles per second in a uniform magnetic field of \( 2 \times 10^{-2} \, T \) about an axis perpendicular to the field. The peak value of the induced emf is:

The total number of degrees of freedom associated with \( 2 \, cm^3 \) of Nitrogen gas at normal temperature and pressure is:
[Given Avogadro number as 'N']

The unit of universal gravitational constant is :

In the normal adjustment of an astronomical telescope, the objective and eyepiece are 36 cm apart. If the magnifying power of the telescope is 8, find the focal lengths of the objective and eyepiece.

The zener voltage in the circuit shown is \( V_Z = 20 \, V \). The load resistance \( R_L = 5k\Omega \) and the resistance \( R_S = 10k\Omega \). If the input voltage is \( V_S = 100 \, V \), then the current through the zener diode in milliampere is:

If the mass numbers of two nuclei are in the ratio \( 5 : 2 \) and their diameters are in ratio \( 2 : 6 \). Then their nuclear densities will be in the ratio

The interference pattern is obtained with two coherent light sources of intensity ratio \( 9 : 1 \). The ratio of \( \frac{I_{MAX}+I_{MIN}}{I_{MAX}-I_{MIN}} \) is \( \frac{\alpha}{\beta} \). The values of \( \alpha \) and \( \beta \) are:

If A, B and C are three different physical quantities with different dimensional formulae, then the combination which can never give a proper physical quantity is

A parallel plate capacitor having plate area 200 cm² and separation 2.0 mm holds a charge of 0.06 µC on applying a potential difference of 60 V. The dielectric constant of the material filled in between the plates is.

If the protons and electrons are the only basic charges in the universe, all the observable charges have to be integral multiples of e. Thus, if an object contains x electrons and y protons, the net charge on the object will be

In a photoelectric experiment, the stopping potential for incident light of wavelength 4000 Å is 2 V. If the wavelength is changed to 3000 Å, the new stopping potential will be approximately:

In a superconducting ring, a persistent current has been flowing without decay for years. This is possible because:

In Optical Fiber communication, the signal is transmitted in the form of:

In a closed hall of volume 5000 m³, the total absorption of the interior surfaces is 200 metric sabin. The reverberation time is:

A bubble of an ideal gas rises from the bottom of a lake to the surface. At the bottom, the pressure is 3 Atm. and the temperature is 7 °C. At the surface, the pressure is 1 atm. and the temperature is 27 °C. If the initial volume of the bubble was $V_0$ what is its volume $V_f$ at the surface?

If the pressure of an ideal gas is doubled and its absolute temperature is halved; the volume will become:

In an Isothermal process:

At constant temperature, the product PV is plotted against pressure P for an ideal gas. The graph obtained is:

The R.M.S. speed of oxygen molecules at 27 °C is $v$. At 927 °C the rms speed will be:

If the volume of a room is doubled and the total absorption is halved, the reverberation time will:

Two identical piano wires, when tuned to a fundamental frequency of 400 Hz, produce no beats. One wire is then slightly tightened, and the beat frequency heard is 2 Hz. What is the new fundamental frequency of the tightened wire?

A source of sound of frequency 500Hz is moving towards an observer with velocity $30m/s$. The speed of sound is $330m/s$. The frequency heard by the observer will be:

A pump is used to deliver water at a certain rate from a given pipe. To obtain twice the volume of water from the same pipe in the same time, by what factor must the power of the motor pump be increased?