Question

The figure shows a wire of resistance 40 Ω bent to form a circle and included in an electric circuit by connecting it from the opposite ends of a diameter of the circle. The current in the circuit is:

• A. 0.125 A
• B. 0.5 A
• C. 0.25 A
• D. 0.1 A

Answer 1

Answer:

B. 0.5 A

The effective resistance of the wire bent in a circle and connected across the diameter ends is 10 Ω, from two parallel halves of 20 Ω each. The current through the circuit is 0.5 A, as given.

This is the typical way to analyze such a problem in circuit theory[derived from electrical principles and Ohm’s law].