Download Q.5. What is a magnetic field?

Assignment : Magnetic effects of electric current
Q.1. Who was Hans Christian Oersted?
Q.2. What happens when compass needle is brought near a bar magnet?
Q.3. A compass needle is bar magnet. Explain.
Q.4. Why do iron filings arrange themselves in a pattern when brought near a magnet?
Q.5. What is a magnetic field?
Q.6. How can we observe relative strength of the magnetic field?
Q.7. Why no two field-lines are found to cross each other?
Q.8. What happens to the deflection of the compass needle placed at a given point if the current in the copper
wire is changed?
Q.9. How is magnetic field influenced by distance?
Q.10. What is the right-hand thumb rule.
Q.11. 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?
Q.12. What does the magnetic field produced by a current-carrying straight wire depend on?
Q.13. What is solenoid?
Q.14. How do we know that the field is uniform inside the solenoid?
Q.15. What is an electromagnet?
Q.16. Which device is used to produce electric current?
Q.17. What happens to the current during the time of short circuit?
Q.18. How is the direction of the magnetic field around a straight conductor carrying current given by?
Q.19. Who established the relation between electricity and magnetism?
Q.20. On what does the Magnetic field produced due to a current through a circular loop depend?
Q.21. Which motors are used in domestic appliances like mixers washing machines and refrigerators?
Q.22. What is the frequency of alternating current in India?
Q.23. What reverses the direction of current in the armature coil of electric motor?
Q.24. Which device is used for converting electrical energy to mechanical energy?
Q.25. What is Alnico?
Q.26. When does the direction of induced current in an AC generator changes?
Q.27. What is an electromagnet?
Q.28. Which scientist suggested that the magnet must also exert an equal and opposite force on the current
carrying conductor?
Q.29. Which rule gives the direction of the motion of a current carrying conductor in a magnetic field?
Q.30. What produces magnetic field in our body?
Q.31. What is the technique of obtaining images of human organs using magnetism called?
Q.32.Who was first to study electromagnetic induction?
Q.33 Which rule gives the direction of the induced current by the magnetic field in a conductor?
Q.34. What is used to detect the presence of current in a circuit?
Q.35. When is potential difference produced in a coil?
Q.36. On which principle electric generators operate?
Q.37. Define magnetic field.
Q.38. Define Electric motor.
Q.39. Define Magnetic field lines.
Q.40. Define electromagnetic induction.
Q.41. What is the important advantage of AC over DC?
Q.42. What is the use of split ring commutator in an electric motor?
Q.43. Which two safety measures are commonly used in electric circuits and appliances?
Q.44. What precaution should be taken to avoid over loading of domestic circuits?
Q.45. When is the force experienced by a current carrying conductor placed in a magnetic field maximum?
Q.46. Name some devices in which electric motors are used?
Q.47. State the form of magnetic field lines around a straight current carrying conductor?
Q.48. Mention ways in which the magnetic field pattern of a bar magnet can be traced?
Q.49. Is it possible to magnetize a steel bar using solenoid? How?
Q.50. What is an electromagnet?
Q.51. What is a compass needle?
Q.52. Discuss the characteristics of magnetic field due to current carrying conductor.
Q. 53. How is the magnetic force useful in studying structure of the matter?
Q.54. What is a galvanometer? How does it work?
Q.55. What is an electric generator? State the principle on which it works.
Q.56. What is the difference between AC Generator and DC Generator.
Q.57. Why are different electrical appliances in a domestic circuit are connected in parallel?
Q.58. Why wires carrying electricity should not be touched bare footed?
Q.59. Why many electrical appliances should not be used simultaneously?
Q.60. Why metal casings of all electrical appliances must be earthed?
Q.61. Why does a circuit catch fire during a short circuit?
Q.62. While working with electricity we must wear gloves made of insulated material and rubber soled shoe.
Why?
Q.63. Explain why the current produced in an AC generator is of alternating nature?
Q.64. Why is the flow of current in the circuit in DC generator in the same direction?
Q.65. Write a note on direct current.
Q.66. What is alternating current?
Q.66. How does current flow in AC generator?
Q.67. How does current flow in AC generator?
Q.67. How does current flow in DC generator?
Q.68. Discuss the use of magnetism in medical sciences.
Q.69. State the production of permanent magnet and its uses.
Q.70. What are the characteristics of magnetic lines of force?
Q.71. Explain the magnetic field due to current through a circular loop.
Q.72. What is electromagnetic induction? How does it generate electric current in the circuit?
Q.73. Write a note on domestic electric circuit.
Q.74. What is earthing? Why is it necessary to earth the metallic appliances?
Q.75. Discuss important safety measures to be followed while using electricity.
Q.76. What is meant by short circuit?
Q.77. What is meant by overloading of circuit?
Q.78. What are the main components of an electric motor?
Q.79. What are the main components of AC generator?