Junior Cert Science - Physics

A charged polythene rod is brought close to a similarly charged polythene rod. Which one of the following is most likely to happen?
1. The rods repel each other
2. The rods attract each other
3. Nothing happens
4. The rods react with each other to form hydrogen gas
Which one of the following statements is CORRECT?
1. An insulator prevents charge from flowing
2. A conductor holds charge
3. The earth is an insulator
4. Lightning rods are made of insulators
A body is negatively charged when
1. it has gained extra electrons
2. it has lost electrons
3. it has lost neutrons
4. it has gained protons
Which one of the following materials is the best insulator?
1. copper
2. iron
3. brass
4. rubber
The pull on the electrons by a battery in an electric circuit is more commonly called the
1. electromotive force of the battery
2. voltage of the battery
3. potential difference of the battery
4. energy of the battery
What energy change takes place when a battery is connected to a light bulb?
1. chemical → electrical → light
2. electrical → heat → light
3. chemical → heat → light
4. electrical → light → heat
Which is the correct symbol for potential difference?
1. V
2. P
3. D
4. R
Which one of the following is the unit of resistance?
1. amp
2. volt
3. ohm
4. joule
Which one of the following statements is CORRECT?
1. Current is measured in amps and has the symbol I
2. Potential difference is measured in amps and has the symbol P
3. Resistance is measured in ohms and has the symbol O
4. Current is measured in volts and has the symbol V
Which one of the following graphs shows the relationship between the potential difference (voltage) and current for a resistor in a circuit at a constant temperature?
Name the measuring instruments X and Y in the circuit shown.
1. X = ammeter, Y = voltmeter
2. X = multimeter, Y = ohmmeter
3. X = voltmeter, Y = ammeter
4. X = voltmeter, Y = ohmmeter
Which one of the following formulae describes the relationship between the potential difference (V) and the current (I) for a resistance (R)
1. V = IR
2. R = V/I
3. V = I/R
4. I = RV
The potential difference across a resistance of 2 ohms in a circuit is 12 volts. What is the value of the current passing through the resistance?
1. 6 amps
2. 24 amps
3. 1/6 amp
4. 14 amps
What is the resistance of a piece of wire when the current flowing through it is 0.12 amps and the potential difference across is 12 volts?
1. 100 ohms
2. 1.44 ohms
3. 12.12 ohms
4. 0.01 ohms
What is the potential difference across a 50 ohm resistor when the current passing through it is 0.1 amps?
1. 5 volts
2. 50.1 volts
3. 0.02 volts
4. 50 volts
A 60 ohm resistance is placed across a 12 volt battery. If an ammeter is placed in the circuit as shown, what current will it read?
1. 0.2 amps
2. 2 amps
3. 48 amps
4. 5 amps
The unit of current, potential difference and resistance respectively are:
1. amps, volts and ohms
2. volts, amps and ohms
3. joules, volts and amps
4. amps joules and ohms
Name the devices labelled A, B and C in the diagram shown
1. A = bulb, B = resistor and C = battery
2. A = battery, B = resistor and C = bulb
3. A = bulb, B = battery and C = switch
4. A = resistance, B = switch and C = battery
The flow of electric charge in one direction only in a circuit is known as:
1. direct current
2. alternating current
3. potential difference
4. resistance
In the USA, the frequency of electric current is 60 Hz. In Ireland and Europe, the frequency of electric current is
1. 50 hertz
2. 100 hertz
3. 240 hertz
4. 10 hertz
In the plug top of an electric appliance, what is the colour of the live wire?
1. brown
2. black
3. blue
4. green/yellow
The green/yellow wire in an electric plug top is known as
1. the earth wire
2. the live wire
3. the blue wire
4. the fuse wire
What are the names of the wires labelled in the diagram?
1. X = neutral, Y = earth
2. X = earth, Y = neutral
3. X = neutral, Y = live
4. X = live, Y = earth
In a domestic fuseboard, a circuit breaker is connected to the
1. live wire
2. earth wire
3. neutral wire
4. neutral and live wires
Another name for the unit of electricity is the
1. kilowatt hour
2. earth wire
3. neutral wire
4. neutral and live wires
If a unit of electricity costs 15 cents, how much will it cost to run a 2 kW electric heater for 3 hours?
1. 90 cents
2. 6 cents
3. 20 cents
4. 75 cents
Which one of the following uses of electricity is the most costly?
1. A 1.5 kW dishwasher on for 2 hours
2. a 20 watt CD player on for 50 hours
3. An 1800 watt kettle left on for 15 minutes
4. A 70 watt computer system on for 1 day
The breaking down of a compound by passing electricity through it is known as
1. electrolysis
2. electromagnetism
3. ultrasound
4. electronics
Which one of the following statements is TRUE?
1. Fuses cannot be used once they blow.
2. Fuses are very expensive to buy.
3. Circuit breakers cannot be reset after an electrical overload.
4. Circuit breakers cannot protect against large amounts of electricity.
Which one of the following is NOT an example of the heating effect of electricity?
1. Electrolysis of water
2. An electric cooker
3. An hair dryer
4. An immersion heater
What solution (electrolyte) is used to electroplate silver onto a spoon?
1. silver nitrate
2. copper sulfate
3. sulfuric acid
4. water
If one unit of electricity costs 15 cents, how much will it cost to run a 25 watt DVD player for 4 hours?
1. 1.5 cents
2. 44 cents
3. 15 euro
4. 115 cents
Which one of the following appliances costs the least to run for the specified time?
1. A 60 watt laptop running for 5 hours.
2. A 2 kW electric heater for 30 minutes
3. A 200 watt electric blanket left on for 3 hours
4. A 100 watt bulb left on for 8 hours
Name the device shown in the diagram
1. Circuit breaker
2. Fuse
3. Switch board
4. Dashboard
The volt is the unit of
1. potential difference
2. electric current
3. temperature
4. resistance
Which one of the following is not used to generate electricity in a power station?
1. plastic
2. gas
3. oil
4. coal
A polythene rod gains a negative charge when it is rubbed with a cloth. Which one of the following statements best explains how this happens?
1. Electrons transfer from the cloth to the polythene rod
2. Electrons transfer to the cloth from the polythene rod
3. Protons transfer to the cloth from the polythene rod
4. Protons transfer from the cloth to the polythene rod
Which one of the following energy changes occurs in a resistor?
1. Electric energy changed to heat energy
2. Electric energy changed to light energy
3. Heat energy changed to electric energy
4. Heat energy changed to light energy
Using the triangle shown, what is the expression used for calculating the current flowing in a circuit?
1. I = V/R
2. I = VR
3. V = IR
4. R = V/I
Which one of the following symbols is that for the variable resistor?
The graph shown is that for voltage against current for a length of resistance wire.What is the resistance of the wire?
1. 5 ohms
2. 0.2 ohms
3. 0.8 ohms
4. 45 ohms
The relationship between potential difference (V), current (I) and resistance (R) for an electrical circuit is known as
1. Ohm's Law
2. Murphy's Law
3. Einstein's Law
4. Boyle's Law
An electric kettle uses 8 amps of electricity when boiling water. Which would be the most appropriate fuse to fit in its plug top?
1. 13 amp
2. 5 amp
3. 3 amp
4. 1 amp

Junior Cert Science - Physics - Electricity

Multiple Choice Quiz