Two long current-carrying wires run parallel to each other. Show that if the currents run in the same direction, these wires attract each other, whereas if they run in opposite directions, the wires repel.

Two long, parallel transmission lines, 40.0 cm apart, carry 25.0-A and 75.0-A currents. Find all locations where the net magnetic field of the two wires is zero if these currents are in the same direction

Two long, straight parallel wires are $10.0 \mathrm{~cm}$ apart and carry $4.00 \mathrm{~A}$ currents in the same direction. Find the magnitude and direction of the magnetic field at
(a) point $P_1$, midway between the wires,
(b) point $P_2, 25.0 \mathrm{~cm}$ to the right of $P_1$.

Streams of charged particles emitted from the sun during unusual sunspot activity create a disturbance in the earth's magnetic field (called a magnetic storm). How can they cause such a disturbance?

Two very long insulated wires perpendicular to each other in the same plane carry currents as shown in Fig. we saw earlier . Find the magnitude of the net magnetic field these wires produce at points $P$ and $Q$ if the 10.0-A current is to the left

At a given instant, a particle with a mass of $5.00 \times 10^{-3} \mathrm{~kg}$ and a charge of $3.50 \times 10^{-8} \mathrm{C}$ has a velocity with a magnitude of $2.00 \times 10^5 \mathrm{~m} / \mathrm{s}$ in the $+y$ direction. It is moving in a uniform magnetic field that has magnitude $0.8 \mathrm{~T}$ and is in the $-x$ direction. What are
(a) the magnitude and direction of the magnetic force on the particle
(b) its resulting acceleration