Revision quiz topic 4,5,6

Which one of the followings does not produce magnetic fields?

• A bar magnet
• A current carrying conductor
• A capacitor
• The Earth

What is a magnetic field?

• Lines with arrows
• Area of magnetic force around a magnet
• Number of magnetic lines flowing through a closed surface
• A region around a magnet where a magnetic force can be experienced

The direction of magnetic field around a current carrying straight wire can be determined by using the right hand grip rule. Which one of the statements is true?

• Thumb represents magnetic field
• Thumb represents electric current
• Other fingers represent magnetic force
• Other fingers represent electric current

By using the right hand grip rule, the direction of magnetic field around a coil carrying current can be determined. What is the direction shows by fingers?

• magnetic force

• electric current

• magnetic field

• North pole

When an electron is released at right angle into a uniform magnetic field, it will move in a

• circular path.
• straight line.
• helical path.
• none of these.

If electric current in a conductor flows in a direction parallel to the magnetic field, the magnetic force acts on the conductor will be

• maximum.
• negative.
• zero.
• infinity.

If currents in two parallel straight wires are flowing in the opposite direction, the force between the wires will be

• attractive.
• repulsive.
• zero.
• attractive or repulsive depending on the material of wires.

If currents in two parallel straight wires are flowing in the same direction, the force between the wires will be

• attractive.
• repulsive.
• zero.
• attractive or repulsive depending on the material of wires.

Which of the following statements is NOT TRUE about magnetic flux?

• It is independent of surface area.
• It is the product of the normal component of the surface area with the magnetic flux density.
• It is zero if the magnetic field is parallel to the surface area.
• It represents the total magnetic field lines passing through a surface area.

An emf will be induced in a coil by

• moving one end of a bar magnet through the coil
• moving the coil toward one end of the bar magnet.
• holding the coil near a second coil while the electric current in the second coil is increasing
• all of the answers