Duration of rotation of pen in the PMMC system depends upon ___________.

The correct answer is: C. Magnitude

The PMMC system is a type of instrument that uses a permanent magnet moving coil (PMMC) to measure electrical signals. The magnitude of the electrical signal determines the deflection of the pen, which is proportional to the magnitude of the signal. The phase angle, frequency, and direction of the electrical signal do not affect the deflection of the pen.

Here is a brief explanation of each option:

• A. Phase angle is the difference between the time when a signal reaches its maximum value and the time when a reference signal reaches its maximum value. The phase angle does not affect the deflection of the pen in a PMMC system.
• B. Frequency is the number of times per second that a signal repeats itself. The frequency does not affect the deflection of the pen in a PMMC system.
• C. Magnitude is the size of a signal. The magnitude of the signal determines the deflection of the pen in a PMMC system.
• D. Direction is the polarity of a signal. The direction of the signal does not affect the deflection of the pen in a PMMC system.