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Worksheetscluster 4
Total questions: 68
Worksheet time: 2hrs 16mins
A thermal protection switch provides protection against what?
Overload
Temperature.
Short circuit.
Overvoltage
A circuit breaker is
power factor correcting device
a device to neutralize the effect of transients
a waveform correcting device
a current interrupting device.
Miniature circuit breaker is a small
fuse
magnetic switch
electromagnetic switch
two way switch
What kind of circuit is in the picture?
open circuit
closed circuit
short circuit
What kind of circuit is in the picture?
open circuit
closed circuit
short circuit
What kind of circuit is in the picture?
open circuit
closed circuit
short circuit
Short circuit occurs when the current takes up
more voltage
less voltage
short path
long path
MCB FULL FORM -
MINIATURE CIRCUIT BREAKER
MODEL CIRCUIT BREAKER
MAXIMUM CIRCUIT BREAKER
WHAT IS THE IMAGE SHOWN -
ULTRA POWER BATTERY
MCB
FUSE
CELL
MCB HELPS AVOID -
SHORT CIRCUITS
OVERLOAD OF ELECTRICAL CURRENT
CHANGE CHANNEL
STORE MONEY
Electric Bell works on the principle of-
Magnetism
Electromagnetism
Gravitation
Static Electricity
The primary function of a fuse is to
Open the circuit
Protect the appliance
Protect the line
Prevent excessive currents from flow through the circuit
The fuse rating is expressed in terms of
Current
Voltage
VAR
KVA
A fuse in a motor circuit provides protection against
Overload
Short-circuit and overload
Open circuit, short-circuit and overload
None of the above
If the earth wire is damaged...
The user will suffer from electric shock
The appliance won't work
The appliance will overheat
What causes a fuse to blow?
High Voltage
High Resistance
High Current
High Power
What is a Series Circuit?
A circuit with more than one path way for current to flow
A circuit with one path way with one switch.
An electric circuit with a single path for current to flow.
Two circuits with one path way for current to flow
What is Parallel Circuit?
A wire that has a battery and a switch.
A circuit that contains more than one path for current flow.
A circuit that contians one path for current flow
A circuit with a switch
What would happen if you added an extra bulb?
Nothing
The light bulb would get dimmer
The light bulb would get brighter
The circuit wouldn't work
What type of circuit is this? Select all that are true.
Series
Parallel
Open circuit
Closed circuit
Which type of circuit is better to have in your home?
Series
Parallel
Either
A _________ is:
A thin piece of metal that melts rapidly when current passing through it reaches a certain limit
Short circuit
Resistor
Fuse
Voltmeter
The voltage of the entire circuit is 18V. What is the voltage of Lamp B
18V
3V
9V
6V
Which situations shows that current could go through the body?
Direct contact with a grounded surface
Direct contact with live parts of the installation
Accidental contact with damaged wires that are seemingly not live
All of the above
At home, you noticed that a portion of an electrical wire is worn out, exposing its metallic part. What do you think might happen if you will just ignore this problem?
short circuit may happen
circuit is of better condition
overloading may not happen
nothing happens when someone touches the wire
Which statement about circuit breaker is not true?
It protects the user from being electrocuted.
it is a switch which will ‘trip’ when there is excess current flowing through.
it creates short circuit.
it cuts off electrical supply when the electrical appliance is damaged.
Which of the following directs any excess current in the metal casing of appliances to the ground?
fuse
earthing
circuit breaker
electric sockets
What is a circuit breaker?
A type of light switch.
A switch used in an electrical appliance that uses large current.
Used to turn on or off the electrical supply to the whole house.
Used to switch off the electrical supply to one part of the circuit when current in that part of the circuit is too large.
If the first bulb in a parallel circuit is removed the remaining bulbs will_______
go out
stay lit
go back on after 3 seconds
blink
If the first bulb in a series circuit is removed, the remaining bulbs will_______
go out
stay lit
explode
bink
A _________ is an example of stored electricity.
circuit
bulb
battery
wire
What does an ammeter measure?
Coulombs
Current
Charge
Amperes
Where in a circuit is an ammeter added?
In parallel
In series
A switch is a device that:
a. short circuits complex circuits
b. holds a fuse
c. has double poles
d. opens or completes a current path
A basic electric circuit is made up of what components?
a. A load, a resistor, and a conductive path for current
b. A voltage source, a load, and a conductive path for current
c. A voltage source, a conductive path for current, and a battery
d. A conductive path for current, a battery, and a copper wire
Ohm's law is a relationship between:
a. voltage, current, and time
b. power, current, and resistance
c. resistance, time, and current
d. voltage, current, and resistance
How a short circuit occurs?
When there is no electric current in the circuit
When hot wires touch the neutral wire
When there is no source in the circuit
When there is no control in the circuit
What is the equation for Ohm's Law
I=RV
V=IR
R=I/V
V=I/R
What is the effect on the current in a simple circuit when both the voltage and the resistance are halved?
It is doubled
It is quadrupled
It is halved
It remains the same
What is an advantage of using a parallel circuit?
It requires only one path for current
If one bulb goes out, the whole circuit goes out
If one bulb goes out, the rest of the bulbs will stay lit
It has dependent paths
What increases resistance in a circuit?
High temp, short wire, thick wire
High temp, long wire, thin wire
Low temp, short wire, thick wire
low temp, long wire, thin wire
A 4.0-ohm resistor has 3.5 amperes passing through it. What is the potential difference in the circuit?
0.88 V
1.1 V
7.5 V
14 V
What is the total resistance in this series circuit?
21 V
7 ohms
60 ohms
17 ohms
Why are overheating cables a hazard?
Could cause a fire
Could cause a electrocution
Could cause a shortcircuit
Could melt the fuse
Where is the Earth wire connected to?
The Live wire
The casing
The neutral wire
The fuse
What is the function or purpose of this item?
To reduce electrical current flow
Provides power
Emits light when a current flows through it
Changes or diverts the direction of the current
What colour is the Earth wire in a 3-pin plug?
Yellow and green
Red
Blue
Brown
What is the job of the live wire?
It brings the potential difference to the device
It keeps the user safe
It completes the circuit
What is the potential difference of the neutral wire?
0V
230V
320V
Explain why each of the wires in a three-core mains cable is insulated.
To keep them warm
To keep them cool
To prevent electrical connection between them inside the cable
When there is too much _________ passing through a fuse it ________.
current, melts
current, explodes
voltage, melts
voltage, explodes
Cable grips are necessary to
stop wires being pulled out
Keep the wires together
act as an insulator
melt when the current gets too high
Name the colour of each of the three wires in a mains plug.
Red
Blue
Green
Brown
Yellow and Green
What is the name given to the blue wire?
Neutral Wire
Earth Wire
Live Wire
The fuse used in an electric appliance should be rated __________ than the operating current.
higher
lower
What is the name of electrical measuring instrument in the figure shown?
Voltmeter
Ammeter
Ohmmeter
AVO meter
What is the name of an electrical measuring instrument that used to measure an electrical quantities like Current , voltage and resistance?
Voltmeter
Ammeter
Ohmmeter
Multimeter
What is the name of an electrical measuring instrument that used to measure an electrical resistance?
Voltmeter
Ammeter
Ohmmeter
Multimeter
