A PMMC (Permanent Magnet Moving Coil) multimeter is commonly used for measuring current and voltage, primarily in DC circuits. When measuring current with a PMMC multimeter, it is crucial to understand how it should be connected correctly in the circuit to avoid damage to the instrument or incorrect readings.

1. Current Measurement:
   • The PMMC meter is used to measure the current flowing through the circuit. For accurate current measurement, the meter must be integrated into the circuit path so that all current flows through it.
   • This is achieved by connecting the PMMC multimeter in series with the circuit. This means that the same current that flows through the circuit also flows through the meter, allowing it to provide an accurate current reading.
2. Connection in Series:
   • By connecting in series, the multimeter becomes part of the circuit, and all the current that needs to be measured passes through the multimeter.
   • This configuration ensures that the multimeter accurately records the magnitude of the current without affecting the circuit's operation significantly as the resistance of a well-calibrated PMMC meter is very low.
3. Wrong Connections (Reasons Why Other Options Are Incorrect):
   • Across the resistor only: This refers to a parallel connection which is incorrect for current measurement as it would bypass the current and not all current would pass through the multimeter.
   • In parallel with the load: Similar to the above, placing the meter parallel would divert most current through the load, rendering the measurement inaccurate and potentially damaging the multimeter.
   • Across the voltage source: This configuration is used for measuring voltage, not current. Connecting a current measuring device across a voltage source can lead to incorrect results and damage to the meter due to high current flow.

Therefore, the correct method to use a PMMC multimeter for measuring current is to connect it in series with the circuit. This correct setup ensures you accurately measure the current flowing through the entire circuit path.