Quesions Corrections 2022

Question 1

Conversion of kilowatts to watts

Answer 1

1KW = 1000W

Question 2

Explain why taking measurements more than once will improve accuracy

Answer 2

Mean can be calculated
Reducing effect of random error

Question 3

Why is a normal thermometer more likely to be misread than a digital thermometer

Answer 3

Parallax error

Question 4

A student rubbed a plastic rod with a cloth, cloth became positively charged. Explain why l

Answer 4

Electrons transferred from the cloth to the rod
And Electrons are negatively charged
So there are more positive charges than negative charges on the cloth

Question 5

Explain why the reading on the mass balance increases when another charged rod is being held stationary above rod on balance

Answer 5

There is an additional force on the balance (increasing the mass reading)
As rod is negatively charged
And rods with like charges repel

Question 6

Explain why a spark jumps between the negatively charged rod and the earthed conductor

Answer 6

Large p.d between the two objects
Causes electrons to move (through the air)
To the conductor

Question 7

Why is step up transformer used

Answer 7

Step up transformers increase the potential difference
And decreases the current
Reducing thermal energy transfer to surroundings
Increasing the efficiency of power transmission

Question 8

What does alpha particle consist of

Answer 8

Two protons and two neutrons