Physics Questions and Answers
If you want to learn more about the nature and properties of matter and energy or you're simply preparing for a Physics exam, these Physics past questions and answers are ideal for you.
If you want to learn more about the nature and properties of matter and energy or you're simply preparing for a Physics exam, these Physics past questions and answers are ideal for you.
Which of the following is a semiconductor
copper
silicon
plastic
Iron
Correct answer is B
Semi-conductor have an elecctric conductivity intermediate in value between that of a pure metal and a good insulator. Silicon is an example
Which of the following is correct about an electric cell?
Primary cell produces a large current for a long time
Secondary cell has a very high internal resistance
Primary cell has a very low internal resistance
Secondary cell has a very low internal resistance
Correct answer is D
About electric cell
Primary cells are used up gradually often the cells are use and it can't be recharged
Secondary cells or accumulated can be recharged and used for a long period of time and their main advantage is that they have low internal resistance
From the diagram above, calculate the energy stored in the capacitor
4.0 x 10−2J
4.0 x 10−4J
8.0 x 10−4J
8.0 x 10−2J
Correct answer is B
c = 8µF, v = 10v
Energy stored = 12 cv2
= 12 × (8 × 10− 6) × 102
= 4 × 10−4