Chap 6

Question 2

Electric current is produced by

Answer 2

-> Movement of wire
-> Movement of the magnet
= magnetic field lines to be cut

Question 3

Characteristics/Differences of Direct Current

Answer 3

• Current flows in one constant direction.
• Produced by batteries, solar cells, Accumulators
• Used in devices like laptops and smartphones.
• More energy is lost over long distances.

Question 4

Characteristics/differences in Alternating current

Answer 4

• Current flows in constantly reversing directions.
• Generated by Power Plants
• Used in home appliances such as toaster, air con
• Less energy lost over long distance

Question 5

function of Cathode Ray oscilloscope

Answer 5

• show differences in the shape of graph, direction of current n voltage change

Question 6

Purpose of transformer

Answer 6

changing the voltage of an alternating current

Question 7

What is transformer made from

Answer 7

• Laminated soft iron core
• Primary coil (left, ac supply)
• Secondary coil (right, load)

Question 8

Characteristic of step up transformer

Answer 8

• Primary voltage(input) across primary coil is lower than secondary voltage (output)
• no. of primary coil turns is lesser than secondary coil

Question 9

Characteristic of step down transformer

Answer 9

• Primary voltage(input) across primary coil is higher than secondary voltage (output)
• no. of primary coil turns is more than secondary coil

Question 10

What happens to the change in voltage of the alternating current in a transformer if the difference between no. of turns in primary coil n the no of turns in secondary coil is increased?

Answer 10

The LARGER the difference between the number of turns in the primary and secondary coil, the BIGGER the difference in the primary and secondary voltage

Question 11

Why r the numbers of turns in primary n secondary coils different

Answer 11

• Transformer can only change the voltage of an alternating current if the number of turns of the primary and secondary coil are different

Question 11

Give 2 example each of home electrical appliance that uses step up transformer & step down transformer

Answer 11

SU: - Microwave
- refrigerator
SD: - Mobile phone charger
- Laptop charger

Question 12

What happens to the voltage of the alternating current before it is transmitted thru the National Grid Network

Answer 12

The voltage of the alternating current is increased

Question 13

When is the voltage of the alternating current the highest

Answer 13

at the National Grid Network

Question 14

What enables electricity to be transmitted to the branch substation when needed?

Answer 14

Switch Zone

Question 15

State 3 safety components in wiring systems in homes

Answer 15

Fuse, Earth Wire, Circuit Breaker

Question 16

Function of fuse

Answer 16

• melts and cuts off electric current supply when excessive current flows thru it

Question 17

One example of cause of short circuit

Answer 17

damaged wire insulator