List of top Physics Questions

If earth suddenly shrinks by one-third of its present radius, the acceleration due to gravity will be

Three bodies, a ring, a solid cylinder and a solid sphere roll down the same inclined plane without slipping. They start from rest. The radii of the bodies are identical. Which of the bodies reaches the ground with maximum velocity?

The ratio of angular speed of a second-hand to the hour-hand of a watch is

In an $L-C-R$ circuit, at resonance

If there were no gravity, which of the following will not be there for a fluid?

Suppose refractive index $\mu$ is given as $ \mu = A + \frac{B}{\lambda^2}$ where A and B are constants and $\lambda$ is wavelength, then dimensions of B are same as that of

In the figure, the ball P is released from rest, when the spring is at its natural length. For the block Q of mass $ 2{{m}_{0}} $ to leave contact with ground at some stage, the minimum mass of P must be

Four identical cells of emf $E$ and internal resistance $r$ are to be connected in series. Suppose if one of the cell is connected wrongly, the equivalent emf and effective internal resistance of the combination is

The electric resistance of a certain wire of iron is $R$. If its length and radius are both doubled, then

A wire when connected to $220\, V$ mains supply has power dissipation $P_1$. Now the wire is cut into two equal pieces which are connected in parallel to the same supply. Power dissipation in this case is $P_2 \, then \, P_2 : P_1$ is

Consider the two cells having emf $E_{1}$ and $E_{2}\left(E_{1}>E_{2}\right)$ connected as shown in the figure. A potentiometer is used to measure potential difference between $P$ and $Q$ and the balancing length of the potentiometer wire is $0.8\, m$. Same potentiometer is then used to measure potential difference between $P$ and $R$ and the balancing length is $0.2\, m$. Then, the ratio $E_{1} / E_{2}$ is

In an aluminum $(Al)$ bar of square cross section, a square hole is drilled and is filled with iron $(Fe)$ as shown in the figure. The electrical resistivities of $Al$ and Fe are $2.7 ? 10^{-8 }\, \Omega m$ and $1.0 ? 10^{-7}\, \Omega m$, respectively. The electrical resistance between the two faces $P$ and $Q$ of the composite bar is

A metal wire of circular cross-section has a resistance $R_1$. The wire is now stretched without breaking so that its length is doubled and the density is assumed to remain the same. If the resistance of the wire now becomes $R_2$ then $R_2 : R_1$ is

If a wire is stretched to make it $0.1\%$ longer, its resistance will

The effective resistance across the points P and Q is

A $ 50\,\Omega $ galvanometer is shunted by a resistance of $ 5\,\Omega . $ The percentage of the total current, which passes through the galvanometer is

Silicon doped with arsenic is

For a given circuit, it is observed that the current $I$ is independent of the value of the resistance $R_6$. Then, the resistance values must satisfy

The resistivity of the material of a potentiometer wire is $5 \times 10^{-6} \Omega\, m$ and its area of cross section is $5 \times 10^{-6} \; m^2$. If $0.2\, A$ current is flowing through the wire, then the potential drop per metre length of the wire is

When two displacements represented by $ y_1 = a \sin \, (\omega \, t)$ and $ y_2 = b \, cos \, ( \omega \, t )$ are superimposed the motion is

The displacement of a particle varies according to the relation $x = 4(\cos \, \pi t + \sin \, \pi t)$. The amplitude of the particle is

Two independent harmonic oscillators of equal mass are oscillating about the origin with angular frequencies $?_1$ and $?_2$ and have total energies $E_1$ and $E_2$, respectively. The variations of their momenta p with positions x are shown in the figures. If $\frac{a}{b} = n^{2}$ and $\frac{a}{R} = n, $ then the correct equation(s) is(are)

A disc of radius a and mass m is pivoted at the rim and is set in small oscillation. If a simple pendulum have the same period as that of the disc, then the length of the simple pendulum should be

A hemisphere is uniformly charged positively. The electric field at a point on a diameter away from the centre is directed