A beam of electrons and protons move parallel to each other in the same direction, then they

One of the two small circular coils, (none of them having any self- inductance) is suspended with a $V-$ shaped copper wire, with plane horizontal. The other coil is placed just below the first one with plane horizontal. Both the coils are connected in series with a $dc$ supply. The coils are found to attract each other with a force. Which one of the following statements is incorrect ?

Two straight parallel wires, both carrying $10$ $ampere$ in the same direction attract each other with a force of $1 \times {10^{ - 3}}\,N$. If both currents are doubled, the force of attraction will be

A closed loop $PQRS$ carrying a current is placed in a uniform magnetic field. If the magnetic forces on segments $PS, SR$ and $RQ$ are $F_1, F_2$ and $F_3$ respectively and are in the plane of the paper and along the directions shown, the force on the segment $QP$ is

Write formula for moving charge $\mathrm{q}$ in magnetic field.

Two long current carrying conductors are placed parallel to each other at a distance of $8 \,cm$ between them. The magnitude of magnetic field produced at mid-point between the two conductors due to current flowing in them is $300 \,\mu T$. The equal current flowing in the two conductors is ...............