Science - Electric Current and Its Effects
Exam Duration: 45 Mins Total Questions : 30
Which symbol of the component is represented here?
- (a)
Switch in the 'ON' position
- (b)
Switch in the 'OFF' position
- (c)
Circuit breaker
- (d)
Battery
Which appliance does not use an electromagnet?
- (a)
T.V.
- (b)
Electric Bell
- (c)
Radio
- (d)
Electric Heater
Which of the following is an electrical conductor?
- (a)
Silver
- (b)
Cork
- (c)
Silver-coloured plastic
- (d)
Wood
Which of the following materials allows electricity to pass through it?
- (a)
Conductor
- (b)
Insulator
- (c)
Rubber
- (d)
Glass
Which of the following is an electrical insulator?
- (a)
Aluminium
- (b)
Cork
- (c)
Gold
- (d)
Copper
Identify the element that is used for making the filament in bulbs
- (a)
Tungsten
- (b)
Copper
- (c)
Aluminium
- (d)
Silver
In which of the following circuits will the bulb or the bulbs glow the brightest?
- (a)
A simple circuit with one bulb and one cell
- (b)
A simple circuit with one bulb and two cells
- (c)
A simple circuit with two bulbs and one cell
- (d)
A simple circuit with two bulbs and two cells
Why does the bulb glow brighter when it is powered by two cells rather than one?
- (a)
The flow of electricity in the circuit is less.
- (b)
The flow of electricity in the circuit is the same
- (c)
The flow of electricity in the circuit is greater
- (d)
The flow of electricity fluctuates
Why do electricians wear rubber gloves?
- (a)
They are soft
- (b)
They are water proof
- (c)
They are insulators
- (d)
They are inexpensive
What are the factors upon which the amount of heat produced in a wire depend
- (a)
Only (i) and (ii)
- (b)
Only (ii) and (iii)
- (c)
Only (i) and (iii)
- (d)
(i), (ii) and (iii)
What happens when a bulb is powered by two cells instead of one in a circuit?
- (a)
The flow of electric current increases
- (b)
The flow of electric current decreases
- (c)
The flow of electric current remains constant
- (d)
The brightness of bulb decreases by half.
The bulb in the circuit shown below does not glow.
Which of following labelled parts is responsible for this?
- (a)
4
- (b)
2
- (c)
3
- (d)
1
Pranati has set up a circuit as shown below.
Which of the following should she put in the blank box marked 'X'to make the bulb glow more brightly?
- (a)
Bulb
- (b)
Cell
- (c)
Key
- (d)
Wire
What happens if you place a compass near a current conducting wire?
- (a)
The needle in the compass gets deflected
- (b)
The needle in the compass gets charged
- (c)
The needle in the compass becomes hot
- (d)
The needle in the compass glows brightly.
Which of the following statements about an electromagnet is NOT true?
- (a)
Insulated wire is wound around it.
- (b)
It works only in the presence of electricity.
- (c)
It is used in fans and radio
- (d)
It is a permanent magnet.
Which of the following does NOT belong to the group formed by the others?
- (a)
Copper coin
- (b)
Steel spoon
- (c)
Wooden ruler
- (d)
Iron nail
Which of the following is NOT true about a series circuit?
- (a)
All the bulbs glow when the circuit is closed
- (b)
If anyone of the bulbs gets fused, then the other bulbs also stop glowing
- (c)
The bulbs do not glow brightly
- (d)
All the bulbs glow independently.
Which of the following devices can be used to measure electric current in a circuit?
- (a)
Speedometer
- (b)
Ammeter
- (c)
Voltameter
- (d)
Battery
Which of the following does NOT produce electrical energy?
- (a)
Generator
- (b)
Motor
- (c)
Battery
- (d)
Cell
Which of the following effects of electric current is made use of in the figure shown below?
- (a)
Heating
- (b)
Chemical
- (c)
Magnetic
- (d)
All of the above
Identify the substance that is easy to magnetise and demagnetise?
- (a)
Steel
- (b)
Cobalt
- (c)
Soft iron
- (d)
Alnico
Which of the following is the advantage of an accumulator over a dry cell?
- (a)
An accumulator is leak proof
- (b)
An accumulator is cheap
- (c)
An accumulator is rechargeable
- (d)
An accumulator is portable.
Which of the following statements is correct of a switch?
- (a)
It allows the flow of electricity
- (b)
It controls the brightness of a bulb.
- (c)
It controls the power of the batteries.
- (d)
It fuses a bulb.
Which of the following objects make use of an electromagnet?
- (a)
- (b)
- (c)
- (d)
Which of these is the symbol for a series combination of cells?
- (a)
- (b)
- (c)
- (d)
Which of these is NOT an insulating material?
- (a)
Saw dust
- (b)
Wool
- (c)
Aluminium foil
- (d)
Glass
Which of the following effects of current in an electric bulb gives us light?
- (a)
Heating
- (b)
Magnetic
- (c)
Chemical
- (d)
All of the above
What is an 'element' in an electrical appliance essentially made up of?
- (a)
A coil of wire
- (b)
An electromagnet
- (c)
An insulating material
- (d)
A safety device such as a fuse
Which of the following electrical appliances does NOT use the magnetic effects of current?
- (a)
- (b)
- (c)
- (d)
Which of the following does NOT help us save electricity?
(i) Switch off the air conditioner and open the refrigerator door to cool the house.
(ii) Use.the electric iron to iron [usrcne or two clothes at a time.
(iii) Connect more than one electric appliance to one power point
- (a)
Only (i) and (ii)
- (b)
Only (ii) and (iii)
- (c)
Only (i) and (iii)
- (d)
(i),(ii) and (iii)