(One Mark Question)
Q.1 Why does the bulk of iron fillings stick to the ends of a bar magnet and not at its centre?
Ans. Because at the ends magnetic strength is maximum and at centres magnetic strength is least.
Q.2 If the frequency of A.C. is 50 Hz. Then how many times it is changing its direction in 1 second?
Ans- 100 Times.
Q.3 What is the pattern of the magnetic field lines around a straight conductor carrying current?
Ans. Concentric circles
Q.4 If the current is flowing in the direction of advancemet of screw, then what is the direction of magnetic field lines?
Ans.In the direction of rotation of screw.
Q.5 How can you say that the magnetic field is uniform inside the solenoid.
Ans. Because field lines are parallel inside the solenoid.
Q.6 Which property of a proton will change while it moves freely in a magnetic field?
Ans. Momentum or Velocity.
Q.7 According to Flemings right hand rule, which part of right hand indicate the movement of conductor?
Q.8 If the no. of turns of a circular current carrying coil are doubled, then how will the magnetic field produced by it changes?
Q.9 In which position the force on conductor is maximum when it is placed in uniform magnetic field?
Ans. When conductor is Perpendicular to field
Q-10 Suppose you are sitting in a room facing one of the wall. An electron beam moving horizontally from your back goes towards the wall in front you and is deflected to your left, what is the direction of magnetic field in the room?
Ans. Vertically upward.
Q-11 A current through a horizontal power line flows in north to south direction.What is the direction of magnetic field (i)at a point directly below it and (ii)at a point directly above it?
Ans. (i) West to East (ii) East to West
Q-12. Electric appliances like electric –press, toaster, fans etc are connected to electric mains through three-pin plug. Why ?
Ans. Electric appliances are connected to three pin plug because heavy appliances require earth wire,so that in case of leakage of any current it goes to earth and user will not get shock. full study links