In making a battery
  • positive terminal of one cell is connected to the negative terminal of the next cell
  • positive terminal of one cell is connected to the positive terminal of the next cell
  • negative terminal of one cell is connected to the negative terminal of the next cell
  • none of the above
Where can the key or switch be placed in the circuit?
  • Left side of the battery
  • Right side of the battery
  • Can be placed anywhere in the circuit
  • Near the positive terminal of the bulb
Which one of the following is based on the heating effect of current?
  • Geyser
  • Hair dryer
  • Immersion rod
  • All of these
The coil of wire contained in an electric heater is known as
  • component
  • element
  • circuit
  • spring
The amount of heat produced in a wire depends on
  • material
  • length
  • thickness
  • all of these
Which mark is necessary on electric appliances?
  • AGMARK
  • ISI
  • FICCI
  • KSK
When an electric current flows through a copper wire AB as shown in Figure, the wire
  • deflects a magnetic needle placed near it
  • becomes red hot
  • gives electric shock
  • behaves like a fuse
Choose the statement which is not correct in the case of an electric fuse.
  • Fuses are inserted in electric circuits of all buildings.
  • There is a maximum limit on the current which can safely flow through the electric circuits.
  • There is a minimum limit on the current which can safely flow in the electric circuits.
  • If a proper fuse is inserted in a circuit it will blow off if current exceeds the safe limit.
Which of the following precautions need not be taken while using electric gadgets / appliances/circuit?
  • We should never touch a lighted electric bulb connected to the mains.
  • We should never experiment with the electric supply from the mains or a generator or an inverter.
  • We should never use just any wire or strip of metal in place of a fuse.
  • We should never turn the switch in ON position.
An electric fuse works on the principle of
  • Magnetic effect of current
  • Chemical effect of current
  • Heating effect of current
  • Electromagnetic induction
Match the column
class7-science-chapter-14-mcq-2.png
  • p -> ii, q-> iv, r -> i, s-> iii
  • p -> i, q -> iii, r -> ii, s -> iv
  • p - > iv, q -> iii, r -> i, s -> ii
  • p -> iv, q -> i, r -> ii, s -> iii
Electric doorbell works on the principle of
  • Magnetic effect of current
  • Chemical effect of current
  • Heating effect of current
  • Electromagnetic induction
Three bulbs A,B and C are connected to battery and switch as shown below Which one of the following is incorrect?
class7-science-chapter-14-mcq-3.png
  • When the switch is ON, all the bulbs A,B and C will glow at the same time.
  • When a switch is in OFF position, Circuit is Open
  • When a switch is in OFF position, No current flows in the circuit
  • When the switch is put ON, the bulbs will glow in the order A, B and C.
(a) If both assertion and reason are true and reason is the correct explanation of the assertion. (b) If both assertion and reason are true, but reason is not correct explanation of the assertion. (c) If assertion is true, but reason is false. (d) If both assertion and reason are false. (e) If reason is true but assertion is false. Assertion: Nichrome is used for the coil of electric heater Reason: Nichrome wire have low melting point and low resistance
  • (a)
  • (b)
  • (c)
  • (d)
  • (e)
which one is incorrect
  • The reason for excessive currents in electrical circuits is the direct touching of wires
  • Excessive current can also be present if we have connection of many devices to a single Socket
  • Fuse wire have low melting point and relatively high resistance
  • None of these
Copper wires are used as connecting wires because
  • Copper wire offers a lower resistance
  • Copper has very high melting point
  • Copper wires are very thick wires
  • Copper wires are very ductile
which of the following element is used for making the filament in bulbs.
  • Copper
  • Aluminium
  • Nichrome
  • Tungsten
which one does not work on heating effect of electric currents
  • Electric Iron
  • Geysers
  • Electric bell
  • Toasters
Match the column
class7-science-chapter-14-mcq-1.png
  • p -> ii, q-> iv, r -> i, s-> iii
  • p -> i, q -> iii, r -> ii, s -> iv
  • p - > iv, q -> iii, r -> i, s -> ii
  • p -> i, q -> iv, r -> iii, s -> ii
Which gas is used to fill the electric bulb
  • Hydrogen
  • Carbon dioxide
  • Argon
  • None of these
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