List of top Physics Questions

An ac source of angular frequency $\omega$ is fed across a resistor R and a capacitor C in series. The current registered is I. If now the frequency of source is changed to $\omega/3$ (but maintaining the same voltage), the current in the circuit is found to be halved. Calculate the ratio of reactance to resistance at the original frequency $\omega$
An a.c. generator consists of a coil of $100$ turns and cross-sectional area of $3 \,m^{2}$, rotating at a constant angular speed of $60$ radian/sec in a uniform magnetic field of $0.04 \,T$. The resistance of the coil is $500$ ohm. What is the maximum power dissipation in the coil?
An A.C. is given by equation $I = I_1\cos\,\omega t + I_2\,\sin \,\omega t$. The r.m.s. value of current is given by
Among the four graphs, there is only one graph for which average velocity over the time interval $ (0, T) $ can vanish for a suitably chosen $ T $ . Which one is it ?
Among the following velocity of sound depend in a gaseous medium__
Among the following pseudo vector is.
Alternating voltage $(V)$ is represented by the equation where $V_m$ is the peak voltage
Along a streamline
$\alpha$-rays are
Alnico is used for making permanent magnets because it has
Air inside a closed container is saturated with water vapour. The air pressure is p and the saturated vapour pressure of water is $\overline{p}$. If the mixture is compressed to one-half of its volume by maintaining temperature constant, the pressure becomes
Air has refractive index 1.0003. The thickness of air column which will have one more wavelength of yellow light (600 nm) than in the same thickness of vacuum is:
According to the Hooke's law, the force required to change the length of a wire by 'l' is proportional to :
According to second postulate of Bohr model, the angular momentum $(L_n)$ of $n^{th}$ possible orbit of hydrogen atom is given by
According to Newtons formula, the speed of sound in air at $STP$ is (Take the mass of $1$ mole of air is $29 \times 10^{-3}\, kg$)
According to Hooke?? law of elasticity, if stress is increased, the ratio of stress to strain
According to Classical theory, the Rutherford model of atom is
According to Laplace correction, the propagation of sound in gas takes place under
According to Bohr hypothesis, discrete quantity is
According to Bohr?? theory, the wave number of last line of Balmer series is $(R = 1.1 \times 10^7 \,m^{-1})$
About $6\%$ of the power of a $100\, W$ light bulb is converted to visible radiation. The average intensity of visible radiation at a distance of $8\, m$ is (Assume that the radiation is emitted isotropically and neglect reflection.
A120 V, 60Hz a.c. power is connected $800\Omega$ non-inductive resistance and unknown capcitance in series. The voltage drop across the resistance is found to be 102V, then voltage drop across eapacitor is
A wire of length $L$, radius $r$ when stretched with a force $F$ changes in length by $l$. What will be the change in the length of a wire of same material having length $2L$, radius $2r$ and stretched by a force $2F$ ?
A wire of resistance R is elongated n-fold to make a new uniform wire. The resistance of new wire
A wire is stretched to double its length. The strain is :