Power Electronics Quiz (BEE503)

The application of a DC/DC type converters is

• Mobile phone

• PDA

• Wind turbines

• All the above

AC/AC converters in a solar power plant use ____ range of frequency.

• 50 Hz to 60 Hz

• 60 Hz to 70 Hz

• 40 Hz to 60 Hz

• 10 Hz to 60 Hz

In a power supply unit, during ON mode, the switch is in ______ mode

• reverse active

• active

• cut off

• saturation

When comparing the operation of a light switch and a dimmer switch, which statement is true?

• A light switch requires a continuous flow of electricity while a dimmer switch does not

• The energy consumption of a light switch is less than a dimmer switch

• A dimmer switch requires a continuous adjustment of the brightness level

• A light switch does not allow for variable levels of brightness

What is the primary function of an inverter in a solar power system?

• Convert DC power to AC power

• Store excess energy

• Regulate voltage levels

• Control power distribution

What is the primary advantage of using power electronics in renewable energy systems?

• Improved efficiency

• Reduced complexity

• Lower cost

• Increased power consumption

What is the primary function of a flyback converter in power electronics?

• Step-up voltage conversion

• Step-down voltage conversion

• Isolation of input and output

• Power factor correction

Explain how pulse-width modulation (PWM) is used in controlling the speed of an electric motor.

• Vary the pulse width based on input voltage

• Vary the frequency of the pulse based on load current

• Vary the amplitude of the pulse based on output power

• Vary the duty cycle of the pulse based on desired output

What is the importance of the duty cycle in controlling the speed of a ceiling fan?

• It determines how fast the fan blades rotate

• It adjusts the angle of the fan blades

• It regulates the amount of air circulation

• It affects the energy consumption of the fan

For a step-down chopper shown in the figure below, dc source voltage = 230 V and the voltage drop across the chopper = 2 V. Find the value of average output voltage for a duty cycle of 0.4.

• 230 V

• 92 V

• 90 V

• 91.2 V