# Electronic Principles – Section 3

1. Which one of the following statements is true for the voltages in a series RL circuit?

A. The total voltages is equal to the sum of the voltages across the resistance and inductance
B. The voltage always has the same amplitude and phase for every part of the circuit
C. The total voltage is less than the sum of the voltages across the resistance and inductance
D. The total voltage lags the total current by less than 90
E. None of the above

Correct Answer:  C. The total voltage is less than the sum of the voltages across the resistance and inductance

2. The core of an electromagnet is said to be in saturation when:

A. the core is permitted to move freely within the coil
B. an increase in current through the coil causes no further increase in the mmf
C. frequent changes in the direction of current through the coil causes heating effects in the core material
D. changing the polarity of the current in the coil changes the polarity of the magnetic field around the core
E. None of the above

Correct Answer:  B. an increase in current through the coil causes no further increase in the mmf

3. As the temperature increases, the current gain

A. increases
B. decreases
C. contant
D. can be any of the above
E. None of the above

4. Assuming 100% efficiency, what is the power being consumed at the secondary winding of the transformer described in question 91?

A. 200 W
B. 1000 W
C. 20 W
D. 100 W
E. None of the above