Which of the following statement is true?

Solution (By Examveda Team)

Let's break down why the other options are incorrect and why option D is correct:

Option A: A galvanometer with low resistance in parallel is a voltmeter - Incorrect
A galvanometer with low resistance in parallel is an ammeter, not a voltmeter. This low resistance is called a shunt resistor.
It allows most of the current to bypass the galvanometer, protecting it from damage while still measuring the current in the circuit.

Option B: A galvanometer with high resistance in parallel is a voltmeter - Incorrect
Adding a high resistance in parallel doesn't achieve the functionality of either a voltmeter or an ammeter.
It would significantly reduce the overall resistance but not in a controlled manner for measuring current.

Option C: A galvanometer with low resistance in series is an ammeter - Incorrect
Adding a low resistance in series with a galvanometer would create a very low overall resistance.
While it would allow current to flow easily, it would not accurately measure the current and could damage the galvanometer.

Option D: A galvanometer with high resistance in series is an ammeter - Correct
To convert a galvanometer into a voltmeter, you need to add a high resistance in series with it.
This high resistance, called a multiplier resistance, limits the current flowing through the galvanometer when the voltmeter is connected across a potential difference.
This allows the galvanometer to measure voltage without drawing a large amount of current from the circuit, which is important for accurate voltage measurement.
It's crucial to understand the difference between ammeters (measuring current) and voltmeters (measuring voltage) and how they are connected in a circuit.