Module 3b revision (AC elec)

Mutual Inductance is NOT dependant on

• permeability

• size of coils

• position

• density

The co-efficient of coupling that represents the ratio of all of the flux from one coil cutting into another:

• 0

• 2

• 1

The ability of a material to retain an amount of residual magnetic field after the magnetising force is removed:

• Coercive Force

• Retentivity

• Saturation

A transformer with turns ratio 1:6 is a "step up" transformer. What is stepped up?

• Current

• Voltage

• Inductance

2 identical inductors of 10H are in series. Total inductance:

• 20H

• 5H

• 100H

RMS value of a 100V peak AC power supply:

• 70.7V

• 7.07V

• 63.6V

How many alternations in a cycle?

• 1

• 2

• 4

In a purely resistive circuit

• current leads voltage

• current lags voltage

• current and voltage are in phase

AC power supply output is 115V at 10kHz

Inductor = 10mH

What is X_L ?

• 628 Ohms

• 100 Ohms

• 314 Ohms

This is the formula for:

• Inductance

• Capacitance

• Inductive Reactance

• Capacitive Reactance