List of top Physics Questions

The variation of the intensity of magnetisation (I) with respect to the magnetising field (H) in a diamagnetic substance is described by the graph

In nuclear fission the percentage of mass converted into energy is about

Surface tension of liquid is $5\,N/m$. If a thin film of area $0.02 \,m^2$ is made in a ring then the surface energy will be :

An object is placed 12 cm to the left of a converging lens of focal length 8 cm. Another converging lens of 6 cm focal length is placed at a distance of 30 cm to the right of the first lens. The second lens will produce

A ray of light travels from an optically denser to a rarer medium. The critical angle for the two media is C. The maximum possible deviation of the ray will be

A Carnot's engine is made to work between $200^\circ \,C$ and $0^\circ \,C$ first and then between $0^\circ \,C$ and $-200^\circ \,C$. The ratio of efficiencies of the engine is the two cases is

In a sample of radioactive material, what percentage of the initial number of active nuclei will decay during one mean life ?

The resultant of two forces, one double the other in magnitude, is perpendicular to the smaller of the two forces. The angle between the two forces is

A cell supplies a current of 0.9 A through a $2\,\Omega$ resistor and a current of 0.3 A through a $7\,\Omega$ resistor. The internal resistance of the cell is

$64$ small drops of mercury, each of radius $r$ and charge $q$ coalesce to form a big drop. The ratio of the surface density of charge of each small drop with that of the big drop is

Two capacitors of capacitance $3\,\mu F$ and $6\,\mu F$ are charged to a potential of $12\, V\, each$. They are now connected to each other, with the positive plate of each joined to the negative plate of the other. The potential difference across each will be

The Cauchy's dispersion formula is

The light reflected by a plane mirror may form a real image

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: