Permanent Magnet Moving Coil (PMMC)

What is the primary function of a PMMC instrument when used as an ammeter?

• A) Measure resistance in an electric circuit.

• B) Detect and compare different circuits.

• C) Measure current in a circuit.

• D) Measure voltage levels.

What is the function of the deflecting system in the principle operation of a PMMC instrument?

• A) It provides the controlling force to move the pointer.

• B) It provides the damping torque for steady-state positioning.

• C) It generates the deflecting torque proportional to the measured quantity.

• D) It brings the pointer back to the zero position.

What is the role of the controlling system in a PMMC instrument?

• A) It provides the damping torque to prevent oscillations.

• B) It generates the deflecting torque to move the pointer.

• C) It opposes the deflecting torque to ensure proportional deflection.

• D) It brings the pointer to the final steady-state position.

Which system in the PMMC instrument ensures that the pointer returns to its zero position when the force is removed?

• A) Damping System

• B) Controlling System

• C) Deflecting System

• D) None of the above

What is the purpose of the controlling force in a PMMC instrument?

• A) To provide the damping torque for steady-state positioning.

• B) To generate the deflecting torque proportional to the measured quantity.

• C) To oppose the deflecting torque for proportional deflection.

• D) To prevent swing or oscillations in the pointer's motion.

Why is the damping system important in a PMMC instrument?

• A) It generates the deflecting torque proportional to the measured quantity.

• B) It brings the pointer back to the zero position.

• C) It provides the controlling force to move the pointer.

• D) It prevents swing or oscillations for quick steady-state positioning.