10. Electrical Circuits

Question 1

Switch

Answer 1

allows current to flow only when open

Question 2

Cell

Answer 2

Supplies electrical energy. The larger line is positive (+)

Question 3

Battery

Answer 3

Supplies electrical energy. A battery is more than one cell. The larger line is positive (+).

Question 4

Diode

Answer 4

A device which allows current to flow in only one direction.

Question 5

Resistor

Answer 5

A resistor restricts the flow of charge

Question 6

Variable resistor

Answer 6

Variable resistors are widely used in electric circuits to adjust the value of current or voltage

Question 7

Lamp

Answer 7

A transducer which converts electrical energy to light

Question 8

Fuse

Answer 8

A safety device which will ‘blow’ (melt) if the current flowing through it exceeds a specified value.

Question 9

Voltmeter

Answer 9

Measures voltage

Question 10

Ammeter

Answer 10

Measures current

Question 11

Thermistor

Answer 11

A transducer which converts temperature (heat) to resistance (an electrical property).

Question 12

LDR

Answer 12

A transducer which converts brightness (light) to resistance (an electrical property)

Question 13

LED

Answer 13

A transducer which converts electrical energy to light.

Question 14

Kirchhoff’s first law

Answer 14

At any junction in a circuit, the total current leaving the junction is equal to the current entering the junction

Question 15

Kirchhoff’s second law

Answer 15

In any circuit, the sum of the electromotive forces is equal to the sum of the potential differences around a closed loop

Question 16

Series circuit

Answer 16

Has only one path for the current, a single loop from one terminal of the source of e.m.f (e.g., a cell) back to the other terminal