Question 1
Figure 1 shows the V-I characteristic curve of a torch bulb
Explain the shape of the graph.
Answer
Resistance increases with temperature due to heating effect of current
Question 2
The size of the pinhole camera is increased. State and explain what happens to the image
Answer
Blurred images/too much light entering through hole
Question 3
Define the term sensitivity
Answer
Sensitivity - Ability to measure small changes using an instrument
Question 4
Why is concave mirrors used as a saloon mirror
Answer
A large erect image
Question 5
Figure 2 shows a graph of magnetisation against magnetising current for two materials A and B.
a) State with a reason, the material which is more suitable for use in a transformer to concentrate the magnetic fields
b) Determine the current required to obtain saturation for the material which is suitable for making a permanent magnet
Answer
a) B - Easily magnetized and easily demagnetised
b) 10A
b) 10A