How does a linear electronic voltage regulator work?

1. A It has a ramp voltage as its output
2. B It eliminates the need for a pass transistor
3. C The control element duty cycle is proportional to the line or load conditions
4. D The conduction of a control element is varied to maintain a constant output voltage

How does a switchmode voltage regulator work?

1. A By alternating the output between positive and negative voltages
2. B By varying the duty cycle of pulses input to a filter
3. C By varying the conductivity of a pass element
4. D By switching between two Zener diode reference voltages

What device is used as a stable voltage reference?

1. A A Zener diode
2. B A digital-to-analog converter
3. C An SCR
4. D An analog-to-digital converter

Which of the following describes a three-terminal voltage regulator?

1. A A series current source
2. B A series regulator
3. C A shunt regulator
4. D A shunt current source

Which of the following types of linear voltage regulator operates by loading the unregulated voltage source?

1. A A constant current source
2. B A series regulator
3. C A shunt current source
4. D A shunt regulator

What is the purpose of Q1 in the circuit shown in Figure E7-2?

1. A It provides negative feedback to improve regulation
2. B It provides a constant load for the voltage source
3. C It controls the current to keep the output voltage constant
4. D It provides regulation by switching or "chopping" the input DC voltage

What is the purpose of C2 in the circuit shown in Figure E7-2?

1. A It bypasses rectifier output ripple around D1
2. B It is a brute force filter for the output
3. C To prevent self-oscillation
4. D To provide fixed DC bias for Q1

What type of circuit is shown in Figure E7-2?

1. A Switching voltage regulator
2. B Common emitter amplifier
3. C Linear voltage regulator
4. D Common base amplifier

How is battery operating time calculated?

1. A Average current divided by capacity in amp-hours
2. B Average current divided by internal resistance
3. C Capacity in amp-hours divided by average current
4. D Internal resistance divided by average current

Why is a switching type power supply less expensive and lighter than an equivalent linear power supply?

1. A The inverter design does not require an output filter circuit
2. B The control circuitry uses less current, therefore smaller heat sinks are required
3. C The high frequency inverter design uses much smaller transformers and filter components for an equivalent power output
4. D It recovers power from the unused portion of the AC cycle, thus using fewer components

What is the purpose of an inverter connected to a solar panel output?

1. A Reduce AC ripple on the output
2. B Maintain voltage with varying illumination levels
3. C Prevent discharge when panel is not illuminated
4. D Convert the panel's output from DC to AC

What is the dropout voltage of a linear voltage regulator?

1. A Minimum input voltage for rated power dissipation
2. B Maximum output voltage drop when the input voltage is varied over its specified range
3. C Minimum input-to-output voltage required to maintain regulation
4. D Maximum that the output voltage may decrease at rated load

Which of the following calculates power dissipated by a series linear voltage regulator?

1. A Input voltage multiplied by input current
2. B Input voltage divided by output current
3. C Voltage difference from input to output multiplied by output current
4. D Output voltage multiplied by output current

What is the purpose of connecting equal-value resistors across power supply filter capacitors connected in series?

1. A Equalize the voltage across each capacitor
2. B Discharge the capacitors when voltage is removed
3. C Provide a minimum load on the supply
4. D All these choices are correct

What is the purpose of a step-start circuit in a high-voltage power supply?

1. A To provide a dual-voltage output for reduced power applications
2. B To compensate for variations of the incoming line voltage
3. C To prevent arcing across the input power switch or relay contacts
4. D To allow the filter capacitors to charge gradually