Electrical Scientific Principles and Technologies Quiz

How can water stored in a reservoir be used to produce electricity?

• By using the water to create a magnetic field

• By using the water to cool down electrical equipment

• By using the water to directly generate electricity

• By using the water to generate steam and turn a turbine

For the typical voltage values used in the United Kingdom, what is 400 kV used for?

• Household appliances

• Low voltage transmission

• High voltage transmission

• Industrial machinery

List three methods of generating electricity using renewable energy.

• Tidal, Nuclear, Geothermal

• Coal, Natural Gas, Oil

• Solar, Wind, Biomass

• Hydroelectric, Nuclear, Geothermal

Why is AC used in preference to DC for most electrical distribution in the UK?

• AC is safer for electrical distribution

• DC is safer for electrical distribution

• DC is more efficient for long-distance transmission

• AC is more efficient for long-distance transmission

List three types of AC motor controller.

• Starter, Inverter, Regulator

• Switch, Amplifier, Converter

• Rectifier, Capacitor, Resistor

• Relay, Diode, Transistor

Why do three-phase motor circuits not usually include a neutral conductor?

• Because the three phases provide a balanced load

• Because the neutral conductor is not necessary for motor circuits

• Because the three phases provide an unbalanced load

• Because the neutral conductor is only used for DC circuits

Protection against electric shock can be provided by?

• Grounding, Overload protection, Short circuit protection

• Insulation, Overvoltage protection, Surge protection

• Voltage regulation, Current limiting, Power factor correction

• Fusing, Earthing, Residual current device

Describe what happens to an RCD under a fault condition?

• It regulates the voltage to prevent overloading

• It shuts off the power if the voltage exceeds a certain limit

• It disconnects the circuit if there is an imbalance in the current

• It increases the current flow to stabilize the circuit

Determine the impedance of the circuit with a coil of inductance 0.2H and resistance 50Ω connected to a 230V 50Hz supply.

• 60.5 ohms

• 50.2 ohms

• 45.6 ohms

• 55.8 ohms

Determine the power factor for a 2kW load that draws 9 A from a 230 V supply.

• 0.86

• 0.90

• 0.82

• 0.78