Magnetic effects

Q1) The most suitable material for making the core of an electromagnet is:

• a) Steel

• b) Iron

• c) Soft iron

• d) Aluminium

Q2) Which of the following is not attracted by a magnet?

• (a) Steel

• (b) Cobalt

• (c) Brass

• (d) Nickel

Q3) When a straight conductor is carrying current:

• a) There are circular magnetic field lines around it

• b) There are magnetic field lines parallel to the conductor

• c) There are no magnetic field lines

• d) None of the above

Q4) A plotting compass is placed near the south pole of a bar magnet. The pointer of the plotting compass will:

• (a) Point away from the south pole

• (b) Point parallel to the south pole

• (c) Point towards the south pole

• (d) Point at right angles to the south pole

Q5) Two magnetic field lines:

• a) Intersect at the neutral point

• b) Never intersect each other

• c) Intersect near north-pole or south pole

• d) Intersect at the midpoint of the magnet

Q6) A student learns that magnetic field strength around a bar magnet is different at every point. Which diagram shows the correct magnetic field lines around a bar magnet?

• option (a)

• option (b)

• option (c)

• option (d)

Q7) The front face of a circular loop of a wire is the North Pole, the direction of current in this face of the loop will be:

• a) Clockwise

• b) Anticlockwise

  
  

• c) Towards North

• d) Towards South

Q8) Which of the following statements is incorrect regarding magnetic field lines?

• (a) The direction of the magnetic field at a point is taken to be the direction in which the north pole of a magnetic compass needle points.

  
  

• (b) Magnetic field lines are closed curves.

• (c) If magnetic field lines are parallel and equidistant, they represent zero field strength.

• (d) Relative strength of the magnetic field is shown by the degree of closeness of the field lines.

Q9) The magnetic field inside a long straight solenoid carrying current:

• a) Is zero

• b) Decrease as we move towards its end

• c) Is the same at all points

• d) Increase as we move towards its end

Q10) A strong bar magnet is placed vertically above a horizontal wooden board. The magnetic lines of force will be:

• (a) Only in the horizontal plane around the magnet

• (b) Only in the vertical plane around the magnet

• (c) In horizontal as well as vertical planes around the magnet

• (d) In all the planes around the magnet