List of top Physics Questions

Two point-charges $ \pm 10\mu C $ are placed $ 5.00\,mm $ apart, forming an electric dipole. Compute electric field at a point on the axis of the dipole $ 15\,cm $ away from the centre on a line passing through the centre dipole.

A slab of material of dielectric constant $K$ has the same area as the plates of a parallel plate capacitor but has a thickness $\left(\frac{3}{4}\right) d$, where $d$ is the separation of the plates. The ratio of the capacitance $C$ (in the presence of the dielectric) to the capacitance $C_{0}$ (in the absence of the dielectric) is

An $8\, \mu F$ capacitor is connected across $220\,V, 50 \,Hz $ line. What is the peak value of the charge through capacitor?

An uncharged capacitor with a solid dielectric is connected to a similar air capacitor charged to a potential of $V_0$. lf the common potential after sharing of charges becomes V, then the dielectric constant of the dielectric must be

Materials suitable for permanent magnet, must have which of the following properties ?

A bar magnet of length $3\, cm$ has points $A$ and $B$ along its axis at distances of $24 \,cm$ and $48\, cm$ on the opposite sides. Ratio of magnetic fields at these points will be

A short bar magnet placed with its axis at $ 30^{\circ} $ with a uniform external magnetic field of $ 0.16\,T $ experiences a torque of magnitude $ 0.032\,J $ . The magnetic moment of the bar magnet will be

Isogonic lines are those for which

The magnetic poles of earth do not coincide with the geographic poles. The discrepancy between the orientation of a compass and true north-south direction is known as magnetic declination.

Particle moves a distance $x$ in time $t$ according to equation $x=(t+5)^{-1}$ The acceleration of particle is proportional to

Two beams of red and violet colours are made to pass separately through a prism of $A = 60^\circ$. In the minimum deviation position, the angle of refraction inside the prism will be

Which of the following graphs cannot possibly represent one dimensional motion of a particle?

A luminous body radiates energy at a rate $3.6 \times 10^{28}$ J/s, then loss of mass of the body per second is

A Vernier calipers has $1\, mm$ marks on the main scale. It has $20$ equal divisions on the Vernier scale which match with $16$ main scale divisions. For this Vernier calipers, the least count is

Band gap of silicon is E$_g$ (Si) of germanium is E$_g$ (Ge) and of carbon is E$_g$ (C). The correct order of band gap is

A $d.c$. battery of $V$ volt is connected to a series combination of a resistor $R$ and an ideal diode $D$ as shown in the figure below. The potential difference across $R$ will be

A man, of mass $60\, kg$, is riding in a lift. The weight of the man, when the lift is accelerating upwards and downwards at $2\, ms ^{-2}$ are respectively (taking $g=10\, ms ^{-2}$ )

In transformer, core is made of soft iron to reduce

A real gas behaves like an ideal gas if its

Two masses $ 8 \,kg $ and $ 12 \,kg $ are connected at the two ends of a string that goes over a frictionless pulley. Calculate the acceleration of the masses and the tension in the string. Take $ g = 10 \,m/s^2 $

Two coherent sources of different intensities send waves which interfere. The ratio of maximum intensity to the minimum intensity is 25. The intensities of the sources are in the ratio

The time period of a simple pendulum of length $L$ as measured in an elevator descending with acceleration $ \frac{g}{3} $ is

The time period of a geostationary satellite is