Class 7 Electric Current And Its Effects CBSE Questions & Answers

Class 7 · Electric Current And Its Effects

This is Science Class 7 Electric Current and its Effects CBSE Questions & Answers. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

1
Electromagnet looses its magnetic property when
  • A
    Current is switched OFF
    Correct
  • B
    Heat is increased
  • C
    Current is switched ON
  • D
    Current is very high
2
In electric bell, bell rings when
  • A
    Electric circuit is incomplete
  • B
    Screw is tighten
  • C
    Hammer hit the gong
    Correct
  • D
    Gong hit the hammer
3
The electric meter measure the current used in
  • A
    Kilowatt-hour
    Correct
  • B
    Watt
  • C
    Ampere
  • D
    Joule/s
4
Which one is bad conductor of electricity?
  • A
    Drinking water
  • B
    Tap water
  • C
    Salty water
  • D
    Distilled water
    Correct
5
When a fuse rated 8 A, it means
  • A
    It will melt if current exceeds 8 A
    Correct
  • B
    It has potential difference of 8V
  • C
    It has a resistance of 8W
  • D
    It will works if current exceeds 8 A
6
Fuse wire is made up of alloys of
  • A
    Low boiling point
  • B
    High boiling point
  • C
    Low melting point
    Correct
  • D
    High melting point
7
When there is a electric current passing through a wire, the particle moving is
  • A
    Positron
  • B
    Proton
  • C
    Neutron
  • D
    Electron
    Correct
8
MCB in electric circuit stands for
  • A
    Maximum current breaker
  • B
    Molar current breaker
  • C
    Minimum current breaker
  • D
    Miniature circuit breaker
    Correct
9
A battery is used to
  • A
    Measure electric potential
  • B
    To produce heat
  • C
    To release electron
  • D
    Maintain potential difference
    Correct
10
Earth wire is connected to those electrical appliances that have
  • A
    Metallic body
    Correct
  • B
    High voltage rating
  • C
    Wooden body
  • D
    Plastic body
11
In electric circuit, ammeter is always connected in _____________ with resistor.
  • A
    Series combination
    Correct
  • B
    Mixed combination
  • C
    Any combination
  • D
    Parallel combination
12
Voltmeter is always connected in parallel because it has
  • A
    High power rating
  • B
    Very low resistance
  • C
    No resistance
  • D
    Very high resistance
    Correct
13
The current passing through a conductor is
  • A
    Inversely proportional to power
  • B
    Inversely proportional to potential difference
  • C
    Directly proportional to potential difference
    Correct
  • D
    Directly proportional to resistance
14
In electric bulb argon or nitrogen gas is filled because they are
  • A
    Chemically uncreative
    Correct
  • B
    Highly reactive
  • C
    Highly compressible
  • D
    Less oxidized
15
Power is inversely proportional to the
  • A
    Charge
  • B
    Current
  • C
    Voltage
  • D
    Resistance
    Correct