PY 131 Module 20 - Electromagnetic Induction

A copper wire will deflect from a magnet when

An electric current passes through it

Faraday’s law

Change the magnetic field intensity in a closed loop and you will induct electricity in that wire

When you double the number of Loops of wire moving into a magnetic field to the voltage you induce is

Doubled

Electric power is transmitted at high voltages because

High currents are wasteful

Magnetic field generates an electric field when

It is changing

The voltage across the input terminal terminals of a transformer is 110 volts. The primary has 50 Loops in the secondary has 25 loops. The voltage the Transformer puts out is..

55 V

An electric motor is very similar to

An electric generator

What happens to a coil of copper wire when a bar magnet is inserted into it

The coil repels the magnet as it enters

Compared to the primary voltage the secondary voltage may be

Larger smaller or the same

What what happens when a magnet is inserted into a coil of wire

The device has a current in it and it becomes an electromagnet

A certain Transformer doubles input voltage. If the primary coil has 10 amps of current then the current and the secondary coil is

5 amps

Metal detectors like the ones used at airports are activated by

Electromagnetic induction

If the primary of a transformer were connected to a DC power source the Transformer would have a voltage output

Only while being connected or disconnected

How can you increase the strength of a current carrying wire

Wrap it around a rod of iron

A Step up Transformer increases

Neither power nor energy

If the same magnet is pushed into a coil with twice the number of loops

Twice as much voltage is induced

The Transformer transforms

Voltage

Transformers use AC so there will be required

Change in magnetic field for operation

A principal difference between an mhd generator and a conventional generator is that the mhd generator

Has no moving parts and operates more efficiently at high temperatures

Power is transmitted at high voltages because the corresponding current in the wires is

Low so overheating of the wires is minimized

The output power of the Transformer is

Equal to the input

What device transforms electrical energy into mechanical energy

A motor

Why would the voltage produced by a generator alternate

The changing magnetic that field that produces it alternates

Disconnect a small voltage battery from a coil of many Loops of wire and a large voltageDisconnect a small voltage battery from a coil of many Loops of wire and a large voltage is produced by

The sudden collapse in the magnetic field

Metal detectors operate via which law

Faraday's Law

The principal advantage of AC power over DC power is

Ac voltage can be transformed via conventional Transformers

What happens when the magnetic field in a closed loop of wire changes

A voltage is induced in the wire

a current is created in the loop of wire

electromagnetic induction occurs

The primary of a transformer is the coil connected to

The power line