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
Coils of heating devices are made up of
  • A
    Mercury
  • B
    Copper
  • C
    Tungsten
  • D
    Nichrome
    Correct
2
Wire carrying current produce attracts the magnetic material due to
  • A
    Heating effect
  • B
    Chemical effect
  • C
    Magnetic field
    Correct
  • D
    All of these
3
Conductor having very high resistance is
  • A
    Good conductor
  • B
    Semi conductor
  • C
    Insulator
    Correct
  • D
    Resistor
4
Potential difference is created in a electric circuit due to
  • A
    Voltmeter
  • B
    Switch
  • C
    Cell or battery
    Correct
  • D
    Conductor
5
Heating effect of electric current is used in
  • A
    Switch
  • B
    Bread toaster
    Correct
  • C
    Earth wire
  • D
    Electric watch
6
Fuse wire is used in electric circuit to prevent
  • A
    Prevent the insulator
  • B
    Electrical appliances and circuit
    Correct
  • C
    Us from electric shock
  • D
    Prevent the ammeter
7
The metal which is poor conductor of electricity is
  • A
    Iron
  • B
    Mercury
    Correct
  • C
    Gold
  • D
    Aluminium
8
A device that break the electric circuit in case of excess current is called
  • A
    Switch
  • B
    Fuse wire
    Correct
  • C
    Voltmeter
  • D
    Earth wire
9
Which of the following metal is best conductor of electric current?
  • A
    Silver
    Correct
  • B
    Copper
  • C
    Aluminium
  • D
    Iron
10
A device that converts the electrical energy into heat energy is
  • A
    Heater
    Correct
  • B
    Fan
  • C
    Motor
  • D
    MP3
11
Nichrome is used a coil of heater because
  • A
    Low resistance and high melting point
  • B
    It has high resistance and high melting point
    Correct
  • C
    High resistance and low melting point
  • D
    Low resistance and high melting point
12
Combination of two or more cell in series is called
  • A
    Power
  • B
    Earth wire
  • C
    Fuse
  • D
    Battery
    Correct
13
Closed and continuous path of electric current is called
  • A
    Electric circuit
    Correct
  • B
    Electronic path
  • C
    Electric path
  • D
    Closed circuit
14
coming together of live wire and fuse wire in a circuit is called
  • A
    Overloading
  • B
    Earthing
  • C
    Short circuit
    Correct
  • D
    Circuit breaker
15
In electrical wiring, the wire with black insulation is usually
  • A
    Neutral wire
    Correct
  • B
    Live wire
  • C
    Fuse wire
  • D
    Earth wire