Magnetism 1. Destroying the magnetic properties of a magnet is called? De-hammering Magnetization Demagnetization NoneQuestion 1 of 37 2. Magnetic materials which are difficult to magnetize but once magnetized retain their magnetism for a long time are said to be:- Hard magnetic materials Soft magnetic materials Ferromagnetic materialsAlloy materialsQuestion 2 of 37 3. Name the biggest disadvantage of the stroking method of magnetism? It only creates weak magnets It provides magnets in which one pole is far from the other end It provides magnets in which one pole is nearer to the end of the magnetised material than the otherNone of aboveQuestion 3 of 37 4. A magnetic field line originates from the North Pole and ends at the South Pole. True or False? True False Maybe NoneQuestion 4 of 37 5. Which of the following methods is the sure test for polarity? Attraction Repulsion Suspension Both A and CQuestion 5 of 37 6. State the Clock rule If on viewing one end of the bar, the current flows in clockwise direction then then it is time to rule the clock If on viewing one end of the bar, the current flows in clockwise direction, then that end is the North Pole. If anticlockwise then it is South Pole. If a coil carrying a current is grasped in the right hand such that the fingers point in the direction of a current in the coil, then the thumbs points in the direction. None of the aboveQuestion 6 of 37 7. Which of the following is not an application of a magnet? Used to make compasses Used to make solenoid valves Used to make generators Used to make lampsQuestion 7 of 37 8. Define ferromagnetic materials Materials which are not attracted by a magnet Materials whose magnetism is temporary Materials which are strongly attracted by a magnet i.e. cobalt and iron All of aboveQuestion 8 of 37 9. Which of the following is not a property of magnets When a magnet is suspended on a thread it shall rest with one end pointing to the north direction of the earth and the other end to the south direction of the earth. A magnet has 2 ends where the power of attraction is greatest A magnet attracts magnetic materials and does not attract non-magnetic materialsMagnetism is a basic physical quantityQuestion 9 of 37 10. In the stroking method of magnetisation, the end of the material i.e. needle where the magnet finishes the stroking pattern acquires an opposite polarity to that of the stroking end of the magnet? True False Maybe NoneQuestion 10 of 37 11. Which of the following is not a method of magnetization? Induction De-hammering Stroking Electrical methodQuestion 11 of 37 12. A magnet is an object which attracts magnetic materials such as cobalt, iron and nickel. True False Maybe NoneQuestion 12 of 37 13. Attraction in a magnet only occurs:- Between two unlike poles of a magnet Between two like poles of a magnet Between a magnet and un-magnetized magnetic material Both A and CQuestion 13 of 37 14. Define the neutral point? It is an area where there is no field at all An area where the resultant magnetic field is zero An area of great magnetic effect Both A and BQuestion 14 of 37 15. Explain how you can demagnetize a magnet using hammering method? By using a large hammer and striking it severally By hammering a magnet in a north-south direction By hammering a magnet in an east-west direction none of the mentioned Question 15 of 37 16. Which of the following is not true when a material like a pin is magnetized by induction method? The end of the pin attracted to the magnet acquires a polarity that is opposite to the magnet's pole.The lower end of the pin acquires a polarity similar to the magnet's pole usedThe pin acquires temporary magnetism None of the aboveQuestion 16 of 37 17. Magnetic shielding is a property of certain materials to concentrate magnetic field hence leaving some areas totally free of magnetic influence? True False Maybe NoneQuestion 17 of 37 18. Which of the following statements is correct about a magnetic field? It is the region or space where magnetic influence is feltIt is weaker further away from the poles It is stronger near the magnetic poles None of the aboveQuestion 18 of 37 19. Define the basic law of magnetism Like poles repel Unlike poles attract Like poles attract None of the aboveQuestion 19 of 37 20. Name two ways in which the polarity of a material which has been magnetized by electrical method can be determined? Clock rule method Right hand rule Left hand rule All of the aboveQuestion 20 of 37 21. Why are electrical measuring instruments and watches covered by soft iron rings? To shield them against stray magnetic fields To decorate them To repel stray magnetic fields None of the aboveQuestion 21 of 37 22. Which of the following method is not a demagnetization method? Hammering a magnet in an east-west direction Heating Electrical method InductionQuestion 22 of 37 23. State the Right-Hand Grip rule as applied to electromagnets If a coil carrying a current is grasped in the right hand such that the fingers point in the direction of current in the coil, then the thumb points in the direction of South Pole. If a coil carrying a current is grasped in the right hand such that the fingers point in the direction of current in the coil, then the thumb points in the direction of the North pole of the magnetic field generated by the current. If on viewing one end of the bar, the current flows in clockwise direction, then that end is North Pole. If anticlockwise then it is South Pole. None of aboveQuestion 23 of 37 24. How can you test the polarity of a magnet? By using a magnet whose poles is already known By bringing the unknown magnet near the known poles of a magnet By suspending the unknown magnet by a threadNot sure of the correct answerQuestion 24 of 37 25. The direction of the magnetic field at a point is the direction which a free North Pole would move if placed at that point in the field? True False Maybe NoneQuestion 25 of 37 26. The path along which a north pole would move if free to do so is called? Magnetic field Magnetic lineMagnetic line of force Magnetic effectQuestion 26 of 37 27. What happens when you heat a magnet? It loses it magnetic propertiesIt disorients its magnetic dipoles It changes magnetic poles All of the aboveQuestion 27 of 37 28. Why is repulsion the only sure test of polarity of an unknown Magnet? Because attraction can occur between 2 unlike poles of a magnetBecause attraction can occur between a magnet and un-magnetized magnetic material Both A and B Because repulsion occurs faster than attractionQuestion 28 of 37 29. A magnet whose field lines are more concentrated means? It is a stronger magnet It is a weaker magnet It is a ferromagnetic None of the aboveQuestion 29 of 37 30. Magnetic materials which are magnetized easily but do not retain their magnetism are said to be:- Hard magnetic material Soft magnetic material Ferromagnetic material Alloy materialQuestion 30 of 37 31. Which of the following statements is INCORRECT about the domain theory? When a magnet i.e. bar magnet is broken into 2 or more pieces, the pieces retain their magnetism Domains comprise of small sub-atomic magnets called dipoles Magnets consists of small magnetic groups called magnetic domainsDipoles in a particular domain point towards different directionsQuestion 31 of 37 32. What is the importance of keepers in the storage of magnets? To prevent magnetic poles of magnets from becoming weaker with time.To avoid self-demagnetization of magnets For shielding purposes None of the mentioned Question 32 of 37 33. The region or space where magnetic influence is felt is called? Magnetic force Magnetic field Magnetic effect NoneQuestion 33 of 37 34. A material is said to be magnetically saturated when:- Most of its domains are aligned in 1 direction All of its domains are aligned in one direction No further magnetism can occur None of the mentionedQuestion 34 of 37 35. Why are magnets placed in an East-West direction when they are being demagnetized? To retain magnetism Not to retain magnetism So that they do not retain some magnetism due to earth's magnetic field All of the aboveQuestion 35 of 37 36. Which of the following is NOT true about magnetic field lines? They are closer together where the field is strongest They originate from South Pole and end at North Pole They repel each other sideways and never intersect one anotherThey originate from North Pole and end at South PoleQuestion 36 of 37 37. A material is said to be magnetized when most of its domains are aligned in 1 direction? False True Maybe NoneQuestion 37 of 37 Loading...
