1. What are magnetic field lines? How is the direction of magnetic field at a point determined? Mention two important properties of magnetic lines.
2. State the rule to determine the direction of a :
(a). Magnetic field produced around a current carrying conductor.
(b). Force experienced by a straight conductor carrying current placed in a magnetic field which is perpendicular to it.
3. State the rule that determines the direction of induced current in straight conductor when a magnetic flux of a magnet around it changes due to the motion of magnet.
4. On what factors does the force experienced by a current carrying conductor placed in a uniform magnetic field depend?
5. A coil of copper wire is connected to a galvanometer. What would happen, If a bar magnet is:
(a). Pushed into the coil with its north pole entering first.
(b). The bar magnet is pulled out of coil.
(c). The bar magnet is held stationary within the coil.
6. What is the function of an earth wire? Why is it necessary to earth metallic appliances?
7. What do you understand by the terms short-circuiting and over loading in an electric supply?
8. What happens when a bar magnet is brought near freely suspended other bar magnet.
9. What is magnetic field? Describe an activity to show the magnetic field around a bar magnet.
10. Describe the suitable activity to show that magnetic effect is produced when current passes through a conductor.
11. What is Maxwell’s right hand grip rule?
12. Describe the magnetic field produced when current it passed through a circular coil.
13. What is solenoid? Describe the magnetic field produced on passing current through a solenoid.
14. State the factors on which the strength of magnetic field produced by a current carrying solenoid depends?
15. State Fleming’s left hand rule.
16. With the help of a labeled diagram, explain the principle of working of an electric motor.
17. What do you understand by electromagnetic induction?
18. Write Faraday’s laws of electromagnetic induction.
19. Name the device, which converts the mechanical energy into electric energy. On which principle does it work? Draw its labeled diagram.
20. Write the characteristics of electricity supplied to domestic use. Why in homes current to two different amperage is being used?
21. Why are the household electric appliances connected in parallel?
22. What is a fuse wire? Why is it supposed a better safety device?
23. State the safety devices and precautions to be used in a domestic circuit.
24. Many electrical appliances and circuits are “earthed” or “grounded”. What is the reason for this?
25. Electricians wear rubber sandals or shoes or rubber hand gloves while working. Why?
26. Consider a circular loop of wire lying in the plane of the table. Let the current pass through the loop clockwise. Apply the right hand rule to find out the direction of the magnetic field inside and outside the loop.
27. How is the strength of the magnetic field at a point near a wire related to the strength of the electric current flowing in the wire?
28. An alternating electric current has a frequency of 50 Hz. How many times does it change its direction in one sec?
29. What is the advantage of the third wire of earth connection in domestic appliances?
30. Explain what is short circuiting and overloading in an electric supply.