List of top Physics Questions

The counting rate observed from a radioactive source at t = 0 seconds was 1600 counts per second and t = 8 seconds it was 100 count per second. The counting rate observed, as counts per second at t = 6 seconds will be :
The count rate from $100\, cm^{3}$ of a radioactive liquid is $c$. Some of this liquid is now discarded. The count rate of the remaining liquid is found to be $c/10$ after three half-lives. The volume of the remaining liquid, in $cm^{3}$, is
The correct statement of the law of equipartition of energy is
The correct statement variation of the conductivity of semiconductors like Ge and Si is given by
The correct plot of the magnitude of magnetic field $\vec{B}$ $vs$ distance $r$ from centre of the wire is, if the radius of wire is $R$
The correct relation between joule and erg is
The core of electromagnet is made of soft iron, because a) the susceptibility of soft iron is very high b) coercivity of soft iron is very low
The constant $k$ in Coulombs law depends on
The conductivity of a superconductor is
The conductivity of intrinsic semiconductors can be increased by adding a suitable impurity. This process is called $(P)$. This can be done with an impurity which is $(Q)$ rich or deficient as compared to the semiconductor. Such impurities introduce $(R)$ defects in them. Electron rich impurities result in $(S)$ type semiconductors while electron deficit impurities result in $(T)$ type semiconductors.
The conduction current is same as displacement current when source is
The concept of displacement current was given by
The comparative strength of macroscopic and microscopic fundamental forces in increasing order is
The coil of the ballistic galvanometer oscillates due to :
The coefficients of self induction of two coils are respectively 2 mH and 3 mH. They are coupled so as to oppose each other. What will be their self inductance if their mutual inductance is 1 mH?
The coefficient of performance of refrigerator, whose efficiency is $25\%$ is
The coefficient of linear expansion of a solid depends upon
The charge on an electron was calculated by
The characteristic's of light which are changed during modulation is/are
The centre of mass of a non uniform rod of length L whose mass per unit length $\lambda=\frac{Kx^2}{L},$ Where k is a constant and x is the distance from one end is :
The cause of the fractional atomic weight of elements is
The capacitors of capacitance $4\,\mu F$ and $6\,\mu F$ are connected in series. A potential difference of $500\, volt$ is applied to the outer plates of capacitor system. Then the charge on each capacitor is equal to
The capacity of a storage cell is expressed in :
The capacitance of a parallel plate capacitor is $5\,\mu F$. When a glass slab is placed between the plates of the capacitor, its potential difference reduces to $1/8$ of the original value. The thickness of the slab is equal to the separation between the plates. The value of the dielectric constant of glass is
The capacitance of a conductor in vacuum is $10\,F$. If it is put in a medium of relative permittivity $5$, the capacitance will be :