D. Long answer questions
1. List four basic components of an electric circuit and draw their standard symbols.
2. What is an electromagnet? Give two uses of electromagnets. Name two factors on which the
strength of an electromagnet depends.
3. Describe a simple experiment to demonstrate that an electric current produces a magnetic effe
4. What is the purpose of using an electromagnet in an electric bell?
Answers
Answer:
(2) If a soft iron bar is placed inside the solenoid, and the current switched on, the iron bar becomes temporarily magnetized. This is the principle of the electromagnet.
The strength of an electromagnet depends on:
The strength of the current passing through the coil, the greater the current, the greater the strength. This because the current increases there is more flow of electrons which in turn increases the magnetic field around it.
The number of turns in the coils, the greater the number of coils, the greater the strength. This is because more the number of coils, more uniformity is obtained in the magnetic field and hence it is more stronger.
Whether the core is made up of a soft or hard magnetic material. Soft iron core magnetizes more quickly than hard magnetic materials like steel.
(3) FOR THIS EXPERIMENT YOU WILL NEED A ELECTRIC COMPASS , A EMPTY MATCHBOX , SOME WIRES OF COPPER , A BATTERY
FIRST PUT THE MAGNETIC COMPASS IN THE MATCH BOX AND COIL THE COPPER WIRE AROUND IT NOW TAKE ANOTHER SET OF WIRE AND JOIN THAT WITH THE END OF THAT WIRE WHICH IS ATTACHED TO MATCHBOX WITH COMPASS THEN ATTACH THE ANOTHER END OF THE WIRE WITH A BATTERY AND OBSERVE .
YOU WILL OBSERVE THAT WHEN THE CURRENT IS PASSED THROUGH THE WIRES THE NEEDLE OF ELECTRIC COMPASS STAR MOVING .
THIS SHOWS THAT ELECTRIC CURRENT PRODUCES MAGNETIC EFFECT .
Answer 1 and 4 are given in the attachment above.
Hope it helps you mate..
