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 is a
  • A
    Both temporary and permanent
  • B
    Temporary magnet
    Correct
  • C
    Natural magnet
  • D
    Permanent magnet
2
Short circuit is caused due to
  • A
    Direct contact of neutral wire and earth wire
  • B
    Direct contact of live wire and guy wire
  • C
    Direct contact of live wire and earth wire
  • D
    Direct contact of live and neutral wire
    Correct
3
Power is inversely proportional to the
  • A
    Voltage
  • B
    Resistance
    Correct
  • C
    Charge
  • D
    Current
4
The substance that easily allow the current to pass through it is called
  • A
    Poor conductor
  • B
    Conductor
    Correct
  • C
    Non-conductor
  • D
    Insulator
5
Connecting too many appliances with single socket may lead to
  • A
    Over drawing
  • B
    Earthling
  • C
    Overloading
    Correct
  • D
    Short circuiting
6
A piece of thing coiled wire used in bulb is called
  • A
    Filament
    Correct
  • B
    Holder
  • C
    Insulator
  • D
    Inert material
7
Two wire of same material and thickness having length of 2 m and 5 m. which one will offer more resistance?
  • A
    5 m wire
    Correct
  • B
    2 m wire
  • C
    No resistance
  • D
    Both have equal resistance
8
Which of the following group contain only conductor?
  • A
    Copper, woolen cloth, graphite
  • B
    Copper, graphite, silver
    Correct
  • C
    Rubber, copper, silver
  • D
    Sea water, tap water, distilled water
9
The device that works on the principle of electromagnetic effect is
  • A
    Radio
  • B
    Generator
    Correct
  • C
    Transformer
  • D
    Transistor
10
Carbon rod in a dry cell is surrounded by a mixture of _____________ and charcoal.
  • A
    Manganese dioxide
    Correct
  • B
    Zinc oxide
  • C
    Carbon dioxide
  • D
    Copper oxide
11
Open circuit is circuit in which
  • A
    Bulb is not present
  • B
    Current is flowing
  • C
    Switch is absent
  • D
    Current is not flowing
    Correct
12
The amount of work done to move unit charge from one point to the other point is called
  • A
    Charge
  • B
    Current
  • C
    Potential difference
    Correct
  • D
    Resistance
13
Which two wire passes through the electric meter?
  • A
    Live wire and neutral wire
    Correct
  • B
    Neutral wire and earth wire
  • C
    Only live wire
  • D
    Live wire and earth wire
14
Length of a wire is doubled than its resistivity will
  • A
    Remain same
    Correct
  • B
    Reduced to halves
  • C
    Get doubled
  • D
    Became one-fourth
15
Fuse is a safety device which is made up of
  • A
    Alloy of high melting point
  • B
    Pure metal of low melting point
  • C
    Pure metal of high melting point
  • D
    Alloy of low melting point
    Correct