1. Why does a compass needle get deflected when brought near a bar magnet ?
2. Draw magnetic field lines around a bar magnet.
3. List the properties of magnetic lines of force.
4. Why don't two magnetic lines of force intersect each other ?
5. 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.
6. The magnetic field in a given region is uniform. Draw a diagram to represent it.
7. State Fleming's left-hand rule.
8. Explain different ways to induce current in a coil.
9. Name some sources of direct current.
10. Which sources produce alternating current ?
11. An electric oven of 2 kW power rating is operated in a domestic electric circuit (220 V) that has a current rating of 5A. What result do you expect ? Explain.
12. Name two safety measures commonly used in electric circuits and appliances.
13. What precaution should be taken to avoid the overloading of domestic electric circuits ?
14. In household circuits, is a fuse wire connected in series or in parallel ?
15. In which wire, (in A.C. circuit), switch is introduced to operate the light?
16. List three sources of magnetic fields.
17. How does a solenoid behave like a magnet? Can you determine the north and south poles of a current carrying solenoid with a help of bar magnet? Explain.
18. When is the force experienced by a current carrying conductor placed in a magnetic field is largest?
19. Think that you are sitting in a chamber with your back to one wall. An electron beam, moving horizontally from back wall towards the front wall, is deflected by a strong magnetic field to your right side. What is the direction of magnetic field?
20. A coil of insulated copper wire is connected to a galvanometer. What will happen if a bar magnet is
(i) pushed into the coil, (ii) withdrawn from inside the coil, (iii) held stationary inside the coil?
21. Two circular coils A and B are placed closed to each other. If the current in the coil A is changed, will some current be induced in the coil B ? Give reason.
22. State the rule to determine the direction of a
(i) magnetic field produced around a straight conductor carrying current.
(ii) force experienced by a current-carrying straight conductor placed in a magnetic field which is perpendicular to it, and
(iii) current induced in a coil due to its rotation in a magnetic field.
23. What is the function of an earth wire ? Why is it necessary to earth metallic appliances ?
24. A current through a horizontal power line flows in east to west direction. What is the direction of magnetic field at a point directly below it and at a point directly above it ?
|1. What is the magnetic effect of current?
|2. How is the magnetic effect of current related to electromagnetism?
|3. How can the direction of a magnetic field produced by a current-carrying conductor be determined?
|4. What is the difference between a permanent magnet and an electromagnet?
|5. How is the magnetic effect of current used in everyday life?