passwella.
Menu

JAMB Physics 2011 Question 47

Question 47

Alternating Current Circuits

In measuring high frequency a.c., the instrument used is the

  1. A.moving iron ammeter
  2. B.hot wire ammeter
  3. C.d.c. ammeter
  4. D.moving coil ammeter.
Show the answer and explanation

Answer: B (hot wire ammeter)

Explanation

A hot-wire ammeter works by the heating effect of the current, which does not depend on frequency, so it can measure high-frequency a.c.