HSC Physics Module 6 Electromagnetism (01/02)

Front

What is the role of a transformer at an electrical power station?

Back

To reduce heating in the transmission lines by stepping up the voltage.

Front

What is the formula for the voltage transformation ratio in a transformer?

Back

The voltage transformation ratio is given by Vp/Vs = Np/Ns, where Vp is primary voltage, Vs is secondary voltage, Np is number of turns in primary coil, and Ns is number of turns in secondary coil.

Front

Define 'electromagnetic induction'.

Back

Electromagnetic induction is the process by which a changing magnetic field induces an electromotive force (EMF) in a conductor.

Front

What is Faraday's Law of Electromagnetic Induction?

Back

Faraday's Law states that the induced EMF in a closed loop is equal to the rate of change of magnetic flux through the loop.

Front

What is Lenz's Law?

Back

Lenz's Law states that the direction of induced current is such that it opposes the change in magnetic flux that produced it.

Front

What is the relationship between current and voltage in a transformer?

Back

In a transformer, the current is inversely proportional to the voltage; as voltage increases, current decreases, and vice versa.

Front

Calculate the secondary voltage of a transformer with a primary voltage of 110 V, primary turns of 60, and secondary turns of 2300.

Back

Vs = Vp * (Ns/Np) = 110 V * (2300/60) = 4.2 x 10^3 V.

Front

What is the purpose of stepping up voltage in power transmission?

Back

Stepping up voltage reduces current in transmission lines, which minimizes energy loss due to heating.

Front

Define 'magnetic flux'.

Back

Magnetic flux is the product of the magnetic field strength and the area perpendicular to the field through which the field lines pass.

Front

What is the unit of magnetic flux?

Back

The unit of magnetic flux is the Weber (Wb).