List of top Physics Questions

If in a circular coil $A$ of radius $R,$ current $i$ is flowing and in another coil $B$ of radius $2 R$ a current $2 i$ is flowing, then the ratio of the magnetic fields, $B_{A}$ and $B_{B}$ produced by them will be :

The inductance between A and D is :

The magnetic field lines due to a bar magnet are correctly shown in

A 100 W bulb $B_1$ and two 60 W bulbs $B_2 \, and\, B_3$, are connected to a 250 V source, as shown in the figure. Now $W_1, W_2 \, and \, W_3$ are the output powers of the bulbs $B_1, B_2$ and $B_3$ respectively. Then,

If an ammeter is to be used in place of a voltmeter, then we must connect with the ammeter :

The resistivity of metal increases with increase in temperature because:

A small block is connected to one end of a massless spring of unstretched length 4.9 m. The other end of the spring (see the figure) is fixed. The system lies on a horizontal frictionless surface. The block is stretched by 0.2 m and released from rest at t = 0. It then executes simple harmonic motion with angular frequency to = $\frac{\pi }{3}$ rad/s. Simultaneously at t = 0, a small pebble is projected with speed v from point P at an angle of 45$^{\circ}$ as shown in the figure. Point P is at a horizontal distance of 10 m from O. If the pebble hits the block at / = 1 s, the value of v is $ (take \, \, g = 10 m /s_2 $

An electron having charge $e$ and mass $m$ is moving in a uniform electric field $E .$ Its acceleration will be

A torque of $30 \,N-m$ is acting on a wheel of mass $5 \,kg$ and moment of inertia $2\, kg-m2$. If wheel starts rotating from rest then, its angular displacement in $10 $ seconds will be:

A body projected with an initial velocity horizontally has kinetic energy K. If it is projected at an angle $ 45{}^\circ $ the initial kinetic energy will be:

An observer can see through a pin-hole the top end of a thin rod of height A, placed as shown in the figure. The beaker height is 3h and its radius h. When the beaker is filled with a liquid up to a height 2h, he can see the lower end of the rod. Then the refractive index of the liquid is

Brilliance of diamond is due to

The green house effect is caused by :

The figure shows a system consisting of (i) a ring of outer radius 3R rolling clockwise without slipping on a horizontal surface with angular speed $?$ and (ii) an inner disc of radius 2R rotating anti-clockwise with angular speed $?/2$. The ring and disc are separated by frictionless ball bearings. The system is in the x-z plane. The point P on the inner disc is at a distance R from the origin, where OP makes an angle of 30$^{\circ}$ with the horizontal. Then with respect to the horizontal surface,

For paramagnetic materials magnetic susceptibility is related with temperature as:

One end of massless rope, which passes over a massless and frictionless pulley $P$ is tied to a hook while the other is free. Maximum tension the rope bear is $360 \,N$. With what value of maximum safe acceleration (in $ms ^{-2}$ ) can a man of $60\, kg$ climb on the rope ?

Minimum deviation is observed with a prism having angle of prism A, angle of deviation $ \delta , $ angle of incident $ i $ and angle of emergence e, then we have generally:

Length of a string tied to two rigid supports is $40 cm .$ Maximum length (wavelength in $cm$ ) of a stationary wave produced on it, is :

When temperature increases, the frequency of a tuning fork :

Velocity of light is equal to

The magnetic needle of a tangent galvanometer is deflected at an angle $30^{\circ}$ due to a magnet. The horizontal component of earth's magnetic field $0.34$ $\times 10^{-4} T$ is along the plane of the coil. The magnetic intensity is

The coefficient of mutual inductance, when magnetic flux changes by $2 \times 10^{-2} Wb$ and current changes by $0.01 A$ is

The breaking stress of a wire depends upon

A second pendulum is kept in a satellite it is revolving around the earth at the height of $3\,R$ from the earth surface. Time period of second pendulum will be: