passwella.
Menu

JAMB Physics 1985 Question 45

Question 45

Magnetism

Which of the following statements is NOT correct?

  1. A.A galvanometer can be converted to an ammeter with a different range by connecting a high resistance in series
  2. B.An electric current always produces a magnetic field
  3. C.Maxwell's screw rule states that if a corkscrew moves in the direction of the current, the hand turns in the direction of the lines of force
  4. D.Electromagnets are used in electric bells and telephone receivers.
  5. E.The lines of force round a straight current carrying conductor are circular.
Show the answer and explanation

Answer: A (A galvanometer can be converted to an ammeter with a different range by connecting a high resistance in series)

Explanation

To make an ammeter a low resistance (shunt) is connected in parallel; a high series resistance makes a voltmeter.