List of top Physics Questions

In a series $LCR$ circuit the voltage across an inductor, capacitor and resistor are $20\,V$, $20\,V$ and $40\,V$ respectively. The phase difference between the applied voltage and the current in the circuit is

In a rocket of mass 1000 kg, fuel is consumed at a rate of $40\,kgs^{-1}$ The velocity of gases ejected from rocket is $5\times10^4\,ms^{-1}$ . The thrust on rocket is

In a series $LCR$ circuit, the phase difference between the voltage and the current is $45^?$. Then the power factor will be

In a pure capacitive circuit if the frequency of ac source is doubled, then its capacitive reactance will be

In a projectile motion, the velocity is perpendicular to acceleration at.

In a plane e.m. wave, magnetic field oscillates sinusoidally with frequency 1 GHz. If its amplitude is $16 \times 10^{-8}$ T then amplitude of electric field is

In a p-n junction diode, the increase in forward voltage of 0.19 V increases the forward current by 37.6 mA. The dynamic resistance of the junction is

In a hydrogen atom the total energy of electron is

In a hydrogen atom, the radius of $n^{th}$ Bohr orbit is $r_n$. The graph between $log(r_n/r_1)$ and $logn$ will be

In a head an elastic collision of a very heavy body moving at $v$ with a light body at rest, velocity of the heavy body after collision is

In a gas equation, PV= RT V refers to the volume of

In a Geiger-Marsden experiment. Find the distance of closest approach to the nucleus of a $7.7 \,MeV$ $\alpha$-particle before it comes momentarily to rest and reverses its direction. ($Z$ for gold nucleus $= 79$)

In a double slit experiment, the distance between the slits is $d$. The screen is at a distance $D$ from the slits. If a bright fringe is formed opposite to one of the slits, its order is

In a double slit experiment using light of wavelength $600\, nm$, the angular width of a fringe on a distant screen is $0.1^{\circ}$. The spacing between the two slits is

In a common base configuration; (transistor circuit) $I_E=1 mA,I_C =0.95 mA$. The value of base current is

In a car lift compressed air exerts a force $F_1$ on a small piston having a radius of 5cm. This pressure is transmitted to a second piston of radius 15cm. If the mass of the car to be lifted is 1350 kg. What is $F_1$ ?

In a ballistics demonstration a police officer fires a bullet of mass $50 \,g$ with speed $200\, ms^{-1}$ on soft plywood of thickness $2 \,cm$. The bullet emerges with only $10\%$ of its initial kinetic energy. The emergent speed of the bullet is

Impedance of the circuit shown below is

Imagine a system of units in which the unit of mass is $10\, kg$, length is $1 \,km$ and time is $1 \,min$. Then 1 joule in this system is equal to

Imagine an atom made up of a proton and a hypothetical particle of double the mass of the electron but having the same charge as the electron. Apply the Bohr atom model and consider all possible transitions of this hypothetical particle to the first excited level. The longest wavelength photon that will be emitted has wavelength $\lambda$ (given in terms of Rydberg constant R for the hydrogen atom) equal to

If $Z=\frac{A^{4}\,B^{1/3}}{CD^{3/2}}$. and $\Delta A$, $\Delta B$, $\Delta C$, and $\Delta D$ are their absolute errors in $A$, $B$, $C$ and $D$ respectively. The relative error in $Z$ is

If Young's modulus of iron be $2 \times 10^{11}N/m^{-2}$ and interatomic distance be $3 \times10^{-10}m^{-2}$, the interatomic force constant will be

If work is done on a system, depends upon initial and final positions only it can be due to

If we add two vectors of equal magnitudes but in opposite directions, we get

If $ W_{1} $ be the work to be done to form a bubble of volume $ V $ from a given solution. The work required to be done to form a bubble of volume $ 2 V $ is