Define mutual inductance and write its SI unit.
A square loop of side 'a' carrying a current `I_2` is kept at distance x from an infinitely long straight wire carrying a current `I_1` as shown in the figure SAQ 41. Obtain the expression for the resultant force acting on the loop.

Explain with reason, in which direction does the current loop KLMN move when kept near an infinitely long straight wire carrying current as shown in figure.

Write an expression for the magnetic field produced by an infinitely long straight wire carrying a current I, at a short perpendicular distance a from itself.

A rectangular loop of sides 25 cm and 10 cm carrying current of 15A is placed with its longer side parallel to a long straight conductor 2.0 cm apart carrying a current of 25A. What is the new force on the loop ?

A rectangular loop of area A, having N turns and carrying a current of I ampere is held in a uniform magnetic field B. Write down the expression for the maximum torque experiened by the loop.

An electron is moving with velocity vecv along the axis of a long straight solenoid carrying current 'I'. What will be the force acting on the electron due to the magnetic field of the solenoid?

A current of 10 A flow around a closed path in a circuit which is in the horizontal plane as shown in the figure. The circuit consists of eight alternative arcs of radii r_(1)=0.08m and r_(2)=0.12m . Each subtends the same angle at the centre. An infinitely long straight wire carrying a current of 10 A is passing throgh the entre of the above circuit vertically with the direction of the current being into the plane of the circuit. What is the force acting on the wire at the centre due to the current in the circuit? What is the force acting on the arc AC and the straight segment CD due to the current at the centre?

Two identical circular wires P and Q each of radius R and carrying current 'I' are kept in perpendicular planes such that they have a common centre as shown in the figure. Find the magnitude and direction of the net magnetic field at the common centre of the two coils.

Obtain an expression for the mutual inductance between a long straight wire and a square loop of side a as shown in Fig. 6.21. :

A straight segment OC(of length L meter) of a circuit carrying a current I amp is placed along the x- axis ( fig.). Two infinitely long straight wires A and B , each extending from z = -oo to +oo , are fixed at y = -a meter and y = +a meter respectively, as shown in the figure. If the wires A and B each carry a current I amp into the plane of the paper, obtain the expression for the force acting on the segment OC. What will be the force on OC if the current in the wire B is reversed?

Two long straight, current-carrying condcutors , PQ and XY, are held a constant distance apart as shown in the figure. The conductors carry the magnitude of current in the same direction . A plan view form above the conductors is shown in the figure. The magnetic flux density B at a distance d from a long straight wire carrying a current I is given by B = 2.0 xx 10^-7 I/d Use this expression to explain why, under normal circumstances, wires carrying alternating current are not seen to vibrate.