Understanding Electrical Power and Calculations

The video tutorial explains the concept of electrical power, how it is calculated, and its significance in electronic devices. It covers the conversion of electrical energy into other forms, such as sound and thermal energy, using examples like a clock radio, computer, and games console. The tutorial also demonstrates power calculations using current and voltage, with practical examples involving a resistor and a bulb. Finally, it discusses the role of fuses in electrical circuits, explaining how they prevent excessive current flow to protect devices.

What does the power rating of an electrical device indicate?

• The amount of electrical energy it consumes per hour

• The amount of electrical energy it transfers per second

• The amount of electrical energy it stores

• The amount of electrical energy it generates

If a device has a power of 5 watts, how much energy does it transfer per second?

• 5 joules

• 20 joules

• 10 joules

• 15 joules

Which formula is used to calculate the power of an electrical device?

• Power = Current / Voltage

• Power = Voltage + Current

• Power = Voltage / Current

• Power = Voltage x Current

A resistor has a current of 0.8 amps and a voltage of 6 volts. What is its power?

• 5.8 watts

• 4.8 watts

• 6.8 watts

• 7.8 watts

How do you calculate the voltage across a bulb with a power of 42 watts and a current of 3.5 amps?

• Multiply power by current

• Subtract current from power

• Divide power by current

• Add power and current

What is the purpose of a fuse in an electrical device?

• To store electrical energy

• To increase the current flow

• To decrease the voltage

• To limit the current flow

Which fuse rating should be used for a toaster drawing a current of 4.5 amps?

• 3 amp

• 5 amp

• 13 amp

• 10 amp