Section 5- Electricity And Circuits

Question 1

Current

Answer 1

Current is the flow of electric charge (eg. Electrons) around the circuit

Question 2

Potential difference

Answer 2

Potential difference is the energy transferred per coulomb of charge that passes between two points in an electrical circuit

Question 3

Resistance

Answer 3

• usually increases with temperature

* when an electrical charge flows through a component it has to work against resistance

Question 4

Equation for charge

Answer 4

Charge= current x time

Question 5

Equation for energy transferred

Answer 5

Energy transferred = charge moved x potential difference

Question 6

Equation for potential difference

Answer 6

Potential difference= current x resistance

Question 7

What happens when resistance increase?

Answer 7

Temperature usually increases as well

Question 8

Series circuit

Answer 8

-

Question 9

Parallel circuit

Answer 9

-

Question 10

Why is heating a circuit not always bad?

Answer 10

-

Question 11

Equation for power

Answer 11

Power= energy transferred/ time

   E P=  —
  T

Question 12

Equation for electrical power

Answer 12

P=IV

Electrical power(W) = current (A) x Potential difference (V)

Question 13

Live wire

Answer 13

• Brown

* the live wire carries the voltage

Question 14

Neutral wire

Answer 14

• Blue

* the neutral wire completes the circuit

Question 15

Earth wire

Answer 15

• Green and Yellow

* the earth wire is for safety and protecting the wiring

Question 16

Fuses

Answer 16

-

Question 17

Circuit breakers

Answer 17

-

Question 18

Insulators

Answer 18

-

Question 19

LDR

Answer 19

Light dependent resistor
•dependent on the intensity of light
•in bright light the resistance falls
•in darkness the resistance is higher

Question 20

Thermistor

Answer 20

• dependent on temperature
• in hot conditions the resistance drops
• in cool conditions the resistance goes up