Electromagnetism PYQ — Page 21

Fuse wire is a wire of :

According to Curie's law, the magnetic susceptibility of a substance at an absolute temperature $T$ is proportional to:

Two 220 volt, 100 watt bulbs are connected first in series and then in parallel. Each time combination is connected to a 220 volt a.c. supply line. The power drawn by the combination in each case respectively will be:

A charge $q$ is located at the centre of a cube. The electric flux through any face is:

A charged particle moves through a magnetic field in a direction perpendicular to it. Then the:

A long solenoid carrying a current produces a magnetic field $B$ along its axis. If the current is doubled and the number of turns per $\mathrm{cm}$ is halved, the new value of the magnetic field is:

An electron is moving around the nucleus of a hydrogen atom in a circular orbit of radius $r$. The coulomb force $\vec{F}$ between the two is: $\left(\right.$ where $\left.K=\frac{1}{4 \pi \varepsilon_0}\right)$

Three capacitors each of capacity $4 \mu \mathrm{F}$ are to be connected in such a way that the effective capacitance is $6 \mu \mathrm{F}$. This can be done by:

In a Wheatstone's bridge all the four arms have equal resistance $R$. If the resistance of the galvanometer arm is also $R$, the equivalent resistance of the combination as seen by the battery is:

Which of the following rays are not electromagnetic waves?

For a series LCR circuit the power loss at resonance is:

Identical charges $(-q)$ are placed at each corner of a cube of side ' $b$ ' then the electrical potential energy of charge (+ $q$ ) which is placed at the centre of cube will be:

To convert a galvanometer into a voltmeter one should connect a:

The velocity of the electromagnetic wave is parallel to:

What is the cause of the 'Greenhouse effect'?

A capacitor of capacitance $C_1$ charged up to $V$ volt and then connected to an uncharged capacitor $C_2$. Then, the final potential difference across each will be:

Specific resistance of a conductor increase with:

Two bar magnets having geometry with magnetic moments $M$ and $2 M$ are first placed in such a way that their similar poles are same side then its time period of oscillation is $T_1$. Now the polarity of one of the magnet is reversed then the time period of oscillation is $T_2$, so:

Some charge is being given to a conductor. Then, its potential:

The magnetic field of a given length of wire for a single turn coil at the centre is ' $B$ ' then, its value for two turns coil for the same wire is:

For a cell, terminal potential difference is $2.2 \mathrm{~V}$ when circuit is open. If it reduces to $1.8 \mathrm{~V}$ when the cell is connected to a resistance of $5 \Omega$. The internal resistance of cell $(r)$ is then:

A charge ' $q$ ' moves in a region where the electric field and the magnetic field both exist, then the force on it is:

Which is having a minimum wavelength?