List of top Physics Questions

In a p-n junction diode, the reverse saturation current doubles for every rise in temperature of:
A particle moves with uniform acceleration along a straight line. The average velocity over an interval is equal to the instantaneous velocity at:
The work done by a conservative force in a closed path is:
The half-life of a radioactive element is 8 days. The fraction remaining after 32 days is:
A convex lens of focal length 20 cm forms a real image at 30 cm from the lens. The object distance is:
A resistor of \(10\,\Omega\) and an inductor of \(0.1\,\text{H}\) are connected in series to a \(100\ \text{V}, 50\ \text{Hz}\) AC source. The impedance of the circuit is:
The escape velocity from the surface of Earth is 11.2 km/s. If the radius of Earth is doubled and mass remains the same, the new escape velocity will be:
In Young's double-slit experiment, the fringe width is 0.6 mm. If the distance between the slits and screen is doubled, and the separation between slits is halved, the new fringe width will be:
The dimensional formula for magnetic flux is:
A body is projected with velocity 20 m/s at an angle of \(30^\circ\) to the horizontal. The maximum height reached by the body is (\(g = 10\ \text{m/s}^2\)):
Two capacitors of capacitance 2 \(\mu\)F and 4 \(\mu\)F are connected in series. The equivalent capacitance is:
The voltage and current of an ac circuit are represented as \( V = 100 \sin(100t) \) volt and \( i = 100 \sin(100t + \frac{\pi}{3}) \) mA respectively. The power dissipated in the circuit is:
Equation of electric field of a plane electromagnetic wave is given as:
\[ E_z = 60 \sin(500x + 1.5 \times 10^{11} t) \, \text{V/m}. \] Write the equation for the magnetic field of the wave.
Calculate the electric field intensity at a point just near the surface of a charged plane sheet, measured from its mid-point. [ \( \sigma = 8.85 \, \mu C/m^2 \) ]
State any four advantages of light emitting diode (LED).
What phenomenon is explained by the wave nature of electromagnetic radiation?
Wave nature of light can be used to explain which phenomenon?
According to Rayleigh, when sunlight travels through atmosphere, the amount of scattering is proportional to $n^{th}$ power of wavelength of light. Then the value of $n$ is
If two light waves of intensities \( I \) and \( 4I \) superimpose at a point with a phase difference of \( \frac{\pi}{2} \), then the resultant intensity at that point is
Two thin convex lenses are kept in contact coaxially. If the focal length of the combination is $4~\text{cm$ and the sum of the focal lengths of the two lenses is $18~\text{cm}$, then the focal length of the lens of low power is}
Images of same size are formed by a convex lens when an object is placed either at 20 cm or 10 cm distance from the lens. The focal length of the lens is
If the far point of a short sighted person is 400 cm, then the power of the lens required to enable him to see very distant objects clearly is
A light ray falls on a rectangular glass slab as shown in the figure. If total internal reflection occurs at the vertical face of the slab at point \( B \), the refractive index of glass is:
A light ray falls on a rectangular glass slab
In an experiment, the angular width of interference fringes for a light of wavelength 5896 Å is found to be $3.5\times10^{-3}$ radian. The wavelength of light for which the angular width of the fringes becomes 10% greater is:
The wavelength of the monochromatic light used in Young's double slit experiment is 550 nm and the screen is placed at a distance of 120 cm from the plane of the slits. If third dark fringe is formed on the screen at a distance of 1.5 mm from the central bright fringe, then the distance of separation between the two slits is