Which of the following statements are not true of a moving-coil milliammeter? I. It can be used to measure alternating current II. It has a linear scale III. It can be adapted to read higher values of currents IV. A resistor connected in parallel with the milliammeter would convert it to a voltmeter
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I and IV only
- II and III only
- III and IV only
- I, II and III only
- I, III and IV only
The correct answer is: A
Explanation
Converting an ammeter to a voltmeter involves increasing the resistance of theammeter. This is done by adding a high resistance in series with the ammeter. Also, A moving coil meter indicates the average (mean) of a varying current through it, which is zero for AC. For this reason moving-coil meters are only usable directly for DC, not AC. Hence, I and IV are false.