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
How many electrons constitute one coulomb of charge?
  • A
    \({\text{6}}.{\text{18 }} \times {\text{ 1}}{0^{{\text{18}}}}\)
  • B
    \({\text{6}}.{\text{25 }} \times {\text{ 1}}{0^{{\text{18}}}}\)
    Correct
  • C
    \({\text{6}}.{\text{25 }} \times {\text{ 1}}{0^{{\text{19}}}}\)
  • D
    \({\text{2}}.{\text{25 }} \times {\text{ 1}}{0^{{\text{18}}}}\)
2
Electrical energy = power x _____________.
  • A
    Current
  • B
    Time
    Correct
  • C
    Resistance
  • D
    Charge
3
When a number of resistors are connected in series total resistance is equal to
  • A
    Product of resistance
  • B
    Inversely proportional resistances
  • C
    Sum of individual resistance
    Correct
  • D
    Difference of resistance
4
In domestic circuit, appliances are generally connected in
  • A
    Parallel combination
    Correct
  • B
    Both parallel and series
  • C
    Series combination
  • D
    Not a specific combination
5
Ammeter is used to measure the current flowing in the circuit. It is always connected in series with resistor because
  • A
    It has low resistance
    Correct
  • B
    It has low melting point
  • C
    It has no resistance
  • D
    It has high resistance
6
Metals are good conductor of electricity because it can
  • A
    No electron
  • B
    Free electros
    Correct
  • C
    Free neutron
  • D
    Free proton
7
Conductor having very high resistance is
  • A
    Insulator
    Correct
  • B
    Good conductor
  • C
    Resistor
  • D
    Semi conductor
8
Human body is _______________ of electricity.
  • A
    Good conductor
    Correct
  • B
    Bad conductor
  • C
    Some time good conductor
  • D
    Neutral
9
A device which prevents or allow the current to flow through it
  • A
    Switch
    Correct
  • B
    Conductor
  • C
    Motor
  • D
    Terminal
10
The amount of work done to move unit charge from one point to the other point is called
  • A
    Charge
  • B
    Resistance
  • C
    Potential difference
    Correct
  • D
    Current
11
Which of the following group contain only conductor?
  • A
    Copper, woolen cloth, graphite
  • B
    Rubber, copper, silver
  • C
    Copper, graphite, silver
    Correct
  • D
    Sea water, tap water, distilled water
12
Resistivity of conductor not depends upon its length or thickness because it is the
  • A
    Independent to length
  • B
    Nature of material
    Correct
  • C
    Depends upon altitude
  • D
    Independent to thickness
13
Silicon and Germanium are elements having
  • A
    Resistivity between conductor and insulator
    Correct
  • B
    Resistivity more than conductor
  • C
    No resistivity
  • D
    Resistivity less than insulator
14
In a house hold 250 unit of electrical energy is consumed in particular months. In standard unit it means that energy consumed is
  • A
    250 KW-h
    Correct
  • B
    250 KJ
  • C
    250 KW/h
  • D
    500 kj/j
15
In electric bulb argon or nitrogen gas is filled because they are
  • A
    Highly compressible
  • B
    Chemically uncreative
    Correct
  • C
    Highly reactive
  • D
    Less oxidized