Physicshard · Past Paper
A wire is bent into a circle. What is the equivalent resistance across the diameter if the original wire had resistance R?
AR/2
BR/4
CR/8
DR
✓ Correct Answer: B — R/4
Across the diameter, the circle splits into two semicircles each with resistance R/2. They are in parallel, so (R/2)/2 = R/4.
Share this question
More from Physics
- A piece of wood floats in water with 1/4th of its volume above the surface. The density of wood is:
- A particle moves along a straight line. After 't' seconds, the distance 's' (in meters) from the starting point is given by s = 8t + 3t^2. Find the velocity at t = 2s.
- Which of these graphs represents uniform motion?
- An object of mass 5 kg is raised through a height of 10 m. What is the work done? (take g=9.8 m/s^2)
- A convex lens forms a real image of a point object on the principal axis. If the upper half of the lens is painted black: