The figure shows two long straight current carrying wire separated by a fixed distance d. The magnitude of current, flowing in each wire varies with time but the magnitude of current in each wire is equal at all times. Which of the following graphs shows the correct variation of force per unit length f between the two wires with current i ?

Question

The figure shows two long straight current carrying wire separated by a fixed distance d. The magnitude of current, flowing in each wire varies with time but the magnitude of current in each wire is equal at all times. Which of the following graphs shows the correct variation of force per unit length f between the two wires with current i ? (A)  (B)  (C)  (D)

Tardigrade Admin · Accepted Answer

The force per unit length is given by f=(μ0 i2/2 π d) i.e., f propto i2

The force per unit length is given by f=2πdμ0​i2​ i.e., f∝i2

The force per unit length is given by $f = \frac{μ _{0} i ^{2}}{2 π d}$
i.e., $f \propto i^{2}$