Domestic Uses and Safety (1)

Question 1

What is the national grid?

Answer 1

box 2 (a system of cables and transformers)

Question 2

The island needs to use the electricity generated by the coal - fired power station at certain times.
Choose one reason why.

Answer 2

3rd box (the power output of wind turbines is unpredictable)

Question 3

A householder always fills the electric kettle to the top, even when only enough boiling water for one small cup of coffee is wanted.
Explain how the householder is wasting money

Answer 3

Bigger volume and so takes more time to boil so more energy is transferred meaning it would cost more money

Question 4

A teacher moves the magnet slowly towards the coil.
Explain why there is a reading on the thermometer

Answer 4

There is a magnetic field around the magnet. The magnetic field changes and cuts through coil so a potential difference is induced across coil forming a complete circuit so a current is induced.

Question 5

• Holds the magnet stationary and moves the coil slowly towards the magnet
• Holds the magnet stationary within the coil
• Moves the magnet quickly towards the coil
• Reverses the magnet and moves it slowly towards the coil

Answer 5

• ammeter
• zero
• greater than before
• same as originally but in the opposite direction

Question 6

Describe how a student would use the circuit to take the readings necessary to determine the resistance of resistor R

Answer 6

• switch on
• read both ammeter and voltmeter
• adjust variables resistor to change the current
• take further readings
• draw graph
• of V against I

Question 7

How does the power of the new shower affect the cost of using the shower?

Answer 7

Cost it higher and more energy is used per second