Two long parallel wires of negligible resistance are connected at one end to a resistance R and at the other end to a constant voltage source of voltage V. The distance between·the axes of the wires is `eta` times greater than the cross-sectional radiµs of each wire. At what value of resistance R, does the resultant force of interaction between the wires will become zero?

A wire of resistance 4R is bent in the form of a circle. What is the effective resistance between the ends of the diameter?

A wire of resistance 6R is bent in the form of a circle. What is the effective resistance between the ends of the diameter?

A wire of resistance 8R is bent in the form of a circle. What is the effective resistance between the ends of a diameter AB?

A wire of resistance 4 R is bent in the form of a circle [Fig 4.4]. What is the effective resistance between the ends of the diameter ?

If an equilateral triangle is made of a uniform wire is resistance R, the equivalent resistance between the ends of sides is

Two long parallel wires of zero resistance are connected to each other by a battery of 1.0V . The separation between the wires is 0.5m . A metallic bar, which is perpendicular toi the wire and of resistance 10Omega moves on these wire when a magnetic field of 0.02 tesla is acting p endicular to the plane containing the wire and the wires. Find the velocity of the bar as a function of time if the mass of the bar is 0.002kg . Find also the steady-state velocity of the bar.