UpperSec_NT_SourcesOfElectricity

In a fossil-fuel power station, the overall energy conversion is

• heat to kinetic

• chemical to heat

• heat to electrical

• chemical to electrical

What is the energy conversion that takes place in the generator in a power station?

• chemical to heat

• heat to kinetic

• kinetic to kinetic

• kinetic to electrical

Identify the various parts of the transformer.

• A

• B

• C

• D

A transformer changes

• voltage.

• frequency.

• power.

• energy.

The core of a transformer is made of

• copper.

• gold.

• silver

• iron

Which of the statements below is true?

• Transformers work only with alternating current.

• Transformers work only with direct current.

• Transformers can work with both direct and alternating current.

• Transformers convert alternating current into direct current.

Why is electricity transmitted in high voltages?

• to reduce energy loss

• to power appliances

• less dangerous to humans

• less prone to fire in transmission cables

Batteries are commonly used in

I laptops

II Bunsen burners

III calculators

IV microwave ovens

V mobile phones

• I, II, III, V

• II, III, IV

• I, III, IV

• I, III, V

Compared to the mains electrical supply, dry cells are

• portable and higher in voltage

• portable and lower in voltage

• not portable and higher in voltage

• not portable and lower in voltage

Dry cells store energy in the form of

• chemical potential energy

• electrical energy

• kinetic energy

• magnetic energy