extend voltage range
measure voltage
compare voltage in a box
none of the above
Answer is Wrong!
Answer is Right!
The correct answer is A.
A volt box is a component used to extend the voltage range of a voltmeter. It does this by providing a higher voltage reference point for the voltmeter to measure against. This allows the voltmeter to measure voltages that are higher than its own rated voltage.
Option B is incorrect because a volt box does not measure voltage. It provides a reference voltage for a voltmeter to measure against.
Option C is incorrect because a volt box does not compare voltage. It provides a reference voltage for a voltmeter to measure against.
Option D is incorrect because a volt box is a real component that is used to extend the voltage range of a voltmeter.