AC Circuit(3)

Multiple Choice

A transformer changes the 120-V voltage at a wall socket to 12 000 V. The current delivered by the wall socket is

• increased by a factor of 100

• decreased by a factor of 100

• neither increase nor decrease.

Multiple Select

A transformer that stepped up the voltage and the current simultaneously would

• produce less power at the secondary coil than was supplied at the primary coil

• produce more power at the secondary coil than was supplied at the primary coil

• produce the same amount of power at the secondary coil that was supplied at the primary coil

• violate the law of conservation of energy.

Multiple Choice

Which statement accurately describes the reverse bias condition of a diode?

• Current flows easily through the diode

• The diode conducts in the opposite direction

• The diode becomes an open circuit

• The diode becomes a short circuit

Multiple Choice

In an N-type semiconductor

• Majority charge carriers are holes

• Majority charge carriers are electrons

• It is formed by doping with impurities missing electrons.

• It has a positive donor impurity concentration

Fill in the Blank

CYU Figure 23.2 shows a full-wave rectifier circuit, in which the direction of the current through the load resistor R is the same for both positive and negative halves of the generator’s voltage cycle. What is the direction of the current through the resistor when

(a)the top of the generator is positive and the bottom is negative?_(L/R)

(b)the top of the generator is negative and the bottom is positive?_(L/R)

L: left to right

R: right to left

Open Ended

A series RCL circuit is composed of a resistor (R = 220 Ω), two identical capacitors (C = 3.50 nF) connected in series, and two identical inductors (L = 5.50 × 10^(-5) H) connected in series. You and your team need to determine:

a)the resonant frequency of this configuration.

b)What are all of the other possible resonant frequencies that can be attained by reconfiguring the capacitors and inductors (while using all of the components and keeping the proper series RCL order)?

c)If you were to design a circuit using only one of the given inductors and one adjustable capacitor, what would the range of the variable capacitor need to be in order to cover all of the resonant frequencies found in (a) and (b)?

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