Two long straight wires $P$ and $Q$ carrying equal current $10\,A$ each were kept parallel to each other at $5\,cm$ distance. Magnitude of magnetic force experienced by $10\,cm$ length of wire $P$ is $F_1$. If distance between wires is halved and currents on them are doubled, force $F_2$ on $10\,cm$ length of wire $P$ will be :
$8 F_1$
$10 F_1$
$F_1 / 8$
$F_1 / 10$
A conductor of length $l$ and mass $m$ is placed along the east-west line on a table. Suddenly a certain amount of charge is passed through it and it is found to jump to a height $h$. The earth’s magnetic induction is $B$. The charge passed through the conductor is:
A circular loop has a radius of $5\, cm$ and it is carrying a current of $0.1\, amp$. Its magnetic moment is
A square shaped wire loop of mass $m$, resistance $R$ and side $a$ moving speed $v_{0}$, parallel to the $X$-axis, enters a region of uniform magnetic field $B$, which is perpendicular to the plane of the loop. The speed of the loop changes with distance $x(x < a)$ in the field, as
A non conducting ring (of mass $m,$ radius $r,$ having charge $Q$) is placed on a rough horizontal surface (in a region with transverse magnetic field). The field is increasing with time at the rate $R$ and coefficient of friction between the surface and the ring is $\mu .$ For ring to remain in equilibrium $\mu$ should be greater than
Two very long, straight, parallel conductors $A$ and $B$ carry current of $5\,A$ and $10\,A$ respectively and are at a distance of $10\,cm$ from each other. The direction of current in two conductors is same. The force acting per unit length between two conductors is: $\left(\mu_0=4 \pi \times 10^{-7}\right.$ SI unit)