PHYSICS 2 EXAM

The total number of magnetic field lines passing through a given area is called

• magnetic flux density

• magnetic flux

• emf

• voltage

1. In a circuit, two or more cells of the same emf connected in parallel order

•  increases the potential difference across a resistance in the circuit.

• decreases potential difference across a resistance in the circuit.

• facilitate drawing more current from the battery system.

• change the emf across the system of batteries.

1. What is the SI unit for emf?

• Farad

• Ohm

• emf

• Volt

1. As per Faraday's law of electromagnetic induction, an emf is induced in a conductor

 whenever it

• lies perpendicular to the magnetic flux.

• lies in a magnetic field.

• cuts magnetic flux.

• moves parallel to the direction of the magnetic field.

 An induced emf is produced in

• a close loop of wires when it remains at rest in a non-uniform static magnetic field

• a close loop of wires when it remains at rest in a uniform static magnetic field.

• a close loop of wires moving at constant velocity in a non-uniform static magnetic field.

• all of the abov

1. A strong permanent magnet is plunged into a coil and left in the coil. What is the effect produced on the coil after a short time?

• The coil winding becomes hot

• The insulation of the coil burns out

• A high voltage is induced

• There is no effect

The Law that states that the direction can induced current is such that its own magnetic field opposes the original change in magnetic flux that induced the current

• Law of conservation of energy

• Faraday’s Law

• Lenz’s Law

• all of the above

1. Lenz’s law concerning the direction of an induced current in a conductor by a magnetic field could be a restatement of?

• Ampere’s Law

• Ohm’s Law

• Tesla’s Law

• Law of Conservation of Energy

 Which of the following statements is NOT true about DC current flow?

• DC current flows from negative to positive.

• DC current flows at a constant rate.

• Battery operated items are examples of DC power

• All DC powered items need to be plugged in.

AC is produced by a generator and its charge is

• positive or negative

• positive and neutral.

• negative and positive.

• negative and negative