Question 1 :
There is a current of 40 amperes in a wire of ${10^{ - 6}}{m^2}$ area of cross-section. If the number of free electron per ${m^3}$ is ${10^{29}},$ then the drift velocity will be
Question 2 :
The current flowing through a wire depends on time as $I=3{ t }^{ 2 }+2t+5$. The charge flowing through the cross-section of the wire in time from $t=0$ to $t=2 s$ is
Question 3 :
A cylindrical capacitor has two co-axial cylinders of length 20 cm and radii 2r and r.Inner cylinder is given a charge 10 $\mu C$ and outer cylinder a charge of -10 $\mu C$.The potential difference between the two cylinders will be.
Question 5 :
Charges $5\mu$C and $10\mu$C are placed $1$m apart. Workdone to bring these charges at a distance $0.5$m from each other is $(k=9\times 10^9SI)$.
Question 6 :
The work done in carrying a charge $Q$ once around a circle of radius $r$ about a charge $q$ at the centre is
Question 7 :
An electric heater consumes $1.1 kW$ power when $220 V$ voltage is applied to it. How much current will be flowing through is ?
Question 8 :
A metal wire is subjected to a constant potential difference. When the temperature of the metal wire increases, the drift velocity of the electron in it
Question 9 :
A unit charge is rotated around a charge of q in a circular path at the distance of r. Then, work done will be:
Question 10 :
A 60 watt bulb carries a current of 0 .5 amp. Th total charge passing through it in 1 hour is
Question 11 :
On moving a charge of 20 coulombs by 2 cm, 2 J of work is done, then the potential difference between the points is:
Question 12 :
Calculate the amount of work done in carrying a charge of $5$ mC against a potential difference of $100 V$. 
Question 13 :
A cylindrical conductor of diameter $0.1 mm$ carries a current of $90 mA$. The current density (in ${ Am }^{ -2 }$ is $\left( \pi \simeq 3 \right) $
Question 14 :
Find $V_{ba}$ if $12$ $J$ of work has to be done against an electric field to take a charge of $10^{-2}$ $C$ from $a$ to $b$.
Question 15 :
The electric potential at point X is 20 V and at point Y is - 40 V. Then, the work done by an external force in moving an electron from X to Y is:
Question 16 :
If n, e, t and m are respectively the density, charge, relaxation time and mass of an electron then the resistance of wire of length / and cross-sectional area A, will be<br>
Question 18 :
An infinite sheet carrying a uniform surface charge density $\sigma$ lies on the xy-plane. The work done to carry a charge q from the point $\overrightarrow{A} = a(\hat{i}+2j+3\hat{k})$ to point $\overrightarrow{B} = a(\hat{i}-2\hat{j}+6\hat{k})$ (where a is constant with the dimension of length and ${\varepsilon}_0$ is the permittivity of free space) is :
Question 19 :
A beam contains $2 \times 10^8$ doubly charged positive ions per cubic centimeter, all of which are moving with a speed of $10^5 m/s$. The current density is
Question 20 :
When a steady current $I$ flows through a resistor of resistance $R$ under a constant potential difference $V$ for time $t$, the electrical work done by charge carrier is $W = $ ___________.
Question 21 :
Which of the following quantities does not change when a resistor connected to a battery is heated due to the current?
Question 22 :
State whether true or false.<br>Charge will flow from one body to another body even when there is no potential difference between them.<br>
Question 23 :
$10^{19}$ electrons are moving across a conductor having a drift speed of $1.6\times 10^{-4}ms^{-1}$. Then the current density is:
Question 24 :
A metallic resistor is connected across a battery. If the number of collisions of the free electrons with the lattice is somehow decreased in the resistor (for example, by cooling it), the current will
Question 25 :
A current of $4.8\ A$ is following in a conductor. The number of electrons passing per sec through the conductor will be:
Question 26 :
The work done in carrying in point charge from one point to the another in an electrostatic field depends on the path along which the point charge is carried.<br>
Question 28 :
A dipole of dipole moment $\overrightarrow{p}$ is kept along an electric field $\overrightarrow{E}$ such that $\overrightarrow{E}$ and $\overrightarrow{p}$ are in the same direction. Find the work done in rotating the dipole by an angle $\pi$.
Question 29 :
Three resistances of magnitude $2, 3$ and $5\ ohm$ are connected in parallel to a battery of $10$ volts and of negligible resistance. The potential difference across 3 resistance will be
Question 30 :
A metal bar of length 1 metre falls from rest under gravity while remaining horizontal with its ends pointing toward magnetic east west. What is the potential difference when it has fallen 10 metres? Horizontal component of earth's field is ${ 1.7\times 10 }^{ -5 }$ Tesla
