Step 1: Understanding the Concept:
A voltmeter is used to measure potential difference across two points and should ideally draw no current from the circuit. To achieve this, it must have a very high total resistance. Step 2: Detailed Explanation:
1. A galvanometer is a sensitive device that can only handle small currents (\(I_g\)).
2. To measure a high voltage (\(V\)), we must limit the current passing through the galvanometer.
3. This is done by connecting a large resistance (\(R\)) in series with the galvanometer (\(G\)).
4. The value is calculated using Ohm's Law: \(V = I_g(G + R)\).
5. Connecting a high resistance in series ensures the device has high impedance and doesn't "load" the circuit being measured. Step 4: Final Answer
A high resistance must be connected in series.