TV3 Ch1 Electricity

• Natuurkunde
• Middelbare school
• vwo
• Leerjaar 3

TV3 Ch1 Electricity

1.1 Generating Electrical energy

Induction of a voltage means

1. Creating a voltage out of nothing
2. Any kind of generation of voltage
3. Generating a voltage through electromagnetism
4. Using heat to generate a voltage

A voltage induced in a generator is an:

1. Alternating voltage
2. Direct voltage
3. Flat voltage
4. High voltage

Some magnets have a core of soft iron. This core:

1. offers support to the windings of the coil
2. is like a storage for magnetism
3. enhances the magnetic field
4. werves no specific purpose

Electrical power is:

1. Energy per unit of time
2. a synonyme for energy
3. Energy times time
4. the strength of a machine

A power of 870 MW is:

1. 870,000 J
2. 870,000 W
3. 870,000,000 J
4. 870,000,000 W

An engine offering 6 kJ in one minute has a power of:

1. 10 W
2. 10 J/s
3. 100 W
4. 100 J/s

1.2 Transporting energy

The correct and complete supply chain of electrical energy looks like:

1. power station - grid - house
2. house - power station - transformer substation
3. power station - grid - transformer substation - house
4. power station - transformer substation - grid - house

Which statement is true for an AC voltage:

1. Effective voltage > Peak voltage
2. Effective voltage < Peak voltage
3. Effective voltage = Peak voltage
4. AC voltage doesn't have an effective voltage.

A transformer with more windings on the secondary coil than on the primary coil ...

1. makes the voltage go up
2. makes the voltage go down
3. makes the current go up
4. makes the current go down

For minimal loss of energy during transport:

1. voltage should be high
2. voltage should be low
3. current should be high
4. current should be low

Which formula is true:

1. Vp/Vs = Np/Ns
2. Vp/Vs = Ns/Np
3. Ip/Is = Np/Ns
4. Ip/Is = Ns/Np

1.3 Electricity in the home

In one 'group' ...

1. the voltage is the same everywhere
2. the voltage can vary
3. the current is the same everywhere
4. none of the above

Every socket is at least connected to:

1. A live wire and a null wire
2. A loaded wire and a neutral wire
3. A charged wire and a null wire
4. A live wire and a neutral wire

The symbol for current, and the symbol for its unit are:

1. I and W
2. I and J
3. I and A
4. P and W

The current through each of the
light bulbs is 1.0 A. The current
coming from the source is:

1. 0.5 A
2. 1.0 A
3. 1.5 A
4. 2.0 A

A 5 W desk lamp is switched on for approximately 2 hours. How much electric energy is 'used'?

1. 3.6 kW
2. 36 kW
3. 3.6 kJ
4. 36 kJ

1 J = . . .

1. 1/3600 kWh
2. 3600 kWh
3. 1/3600000 kWh
4. 3600000 kWh

Electricity and safety

A current of 20-50 mA . . .

1. is not harmful at all
2. causes some tingling sensations
3. can cause some physical problems
4. is potentially deadly

A dry skin has

1. zero contact resistance
2. lower contact resistance than wet skin
3. the same contact resistance as wet skin
4. larger contact resistance than wet skin

What voltage starts to get harmful for a human

1. from 1.5 V onwards
2. from 6 V onwards
3. from 30 V onwards
4. from 230 V onwards

A circuit breaker . . .

1. compares the incoming current to the outgoing current
2. measures the incoming current
3. measures the outgoing current
4. is a manually operated switch

Which one is
the earthing
(grounding) wire?

1. The black one
2. The brown one
3. The yellow/green one
4. The blue one