Understanding Electrical Components and Safety

What does the current-voltage graph of a fixed resistor look like?

• A straight line through the origin

• A curve that starts steep and flattens out

• A horizontal line

• A vertical line

Which component has a current-voltage graph that is a curve starting steep and flattening out?

• Fixed resistor

• Filament lamp

• Diode

• Thermistor

What is the purpose of the earth wire in a three-pin plug?

• To carry the current to the appliance

• To provide a path for electrical current to the ground in case of a fault

• To prevent the plug from overheating

• To supply extra voltage to the appliance

Which pin in a three-pin plug is connected to the live wire?

• The top pin

• The left pin

• The right pin

• The bottom pin

What is the unit of electrical power?

• Volt

• Ampere

• Watt

• Ohm

Which of the following is a safety feature of mains electricity?

• High voltage

• Circuit breakers

• Thin wires

• No insulation

What happens to the resistance of a light-dependent resistor (LDR) as light intensity increases?

• Resistance increases

• Resistance decreases

• Resistance remains constant

• Resistance becomes zero

What is the main characteristic of a thermistor?

• Its resistance decreases with increasing temperature

• Its resistance increases with increasing temperature

• It has a constant resistance

• It conducts electricity only in one direction

Which component allows current to flow in only one direction?

• Resistor

• Diode

• Thermistor

• Filament lamp

What is the main function of a fuse in an electrical circuit?

• To increase the current

• To decrease the voltage

• To protect the circuit by breaking the connection if the current is too high

• To store electrical energy