Electric Current and Its Effects Class 7 MCQs Questions with Answers
I. Choose the correct option.
Question 1.
Which of the devices use a battery?
(a) Torch
(b) Transistor
(c) TV remote control
(d) All of these
Answer
Answer: (d) All of these
Question 2.
Arrangement of cells in a device is
(a) side by side
(b) one after the other
(c) (a) or (b)
(d) none of these
Answer
Answer: (c) (a) or (b)
Question 3.
In an electric circuit, the bulb glows only when the switch is in the
(a) ‘ON’ position
(b) ‘OFF’ position
(c) (a) or (b)
(d) none of these
Answer
Answer: (a) ‘ON’ position
Question 4.
When the switch is in the ‘ON’ position, the electric circuit is said to be
(a) closed
(b) open
(c) complete
(d) both (a) and (c)
Answer
Answer: (d) both (a) and (c)
Question 5.
Which of the following precaution need not be taken while using electric appliances?
(a) Never touch lighted electric bulb connected to mains.
(b) Never experiment with the electric supply from mains.
(c) Never use any wire to replace fuse wire.
(d) Never turn switch in ‘ON’ position.
Answer
Answer: (d) Never turn switch in ‘ON’ position.
Question 6.
In a bulb there is a thin wire called
(a) filament
(b) coil
(c) element
(d) fuse wire
Answer
Answer: (a) filament
Question 7.
When the bulb gets fused, the electric current
(a) flows in the circuit
(b) does not flow in the circuit
(c) sometimes flows and sometimes not
(d) none of these
Answer
Answer: (b) does not flow in the circuit
Question 8.
A glowing bulb becomes warm due to the
(a) heating effect of current
(b) magnetic effect of current
(c) chemical effect of current
(d) physical effect of current
Answer
Answer: (a) heating effect of current
Question 9.
An electric iron is an example of
(a) heating effect of current
(b) magnetic effect of current
(c) chemical effect of current
(d) physical effect of current
Answer
Answer: (a) heating effect of current
Question 10.
The amount of heat produced in a wire depends on its
(a) material
(b) length
(c) thickness
(d) all of these
Answer
Answer: (d) all of these
Question 11.
The electric current has
(a) magnetic effect
(b) heating effect
(c) chemical effect
(d) all of these
Answer
Answer: (d) all of these
Question 12.
Which of the following is being used in place of fuses?
(a) MCB
(b) Nichrome
(c) Filament
(d) Switch
Answer
Answer: (a) MCB
Question 13.
Which of the following is not a reason for excessive currents in electrical circuits?
(a) Direct touching of wires
(b) Short circuiting
(c) Switch in ‘off position
(d) Overloading
Answer
Answer: (c) Switch in ‘off position
Question 14.
When electric current passes through a wire, it behave like a
(a) battery
(b) magnet
(c) fuse
(d) compass needle
Answer
Answer: (b) magnet
Question 15.
Fuse wire is generally made of
(a) tin and lead
(b) nickel and chromium
(c) nickel and copper
(d) chromium and silver
Answer
Answer: (a) tin and lead
II. Fill in the Blanks
Question 1.
A combination of two or more cells is called a ………………..
Answer
Answer: battery
Question 2.
In a battery, the ……………….. terminal of one cell is connected to the ……………….. terminal of another cell.
Answer
Answer: positive; negative
Question 3.
An electric iron works on the principle of ……………….. effect of electric current.
Answer
Answer: heating
Question 4.
The crane in a junkyard separate iron from the junk by using ……………….. effect of electric current.
Answer
Answer: magnetic
Question 5.
The bulb glows as the switch is moved to the ……………….. position.
Answer
Answer: ‘ON’
Question 6.
When the bulb gets fused, its ……………….. breaks.
Answer
Answer: filament
Question 7.
When the switch is in the ‘OFF’ position, the circuit is said to be ……………….. or ……………….. and no current flows through it.
Answer
Answer: open, incomplete
Question 8.
The needle of a compass is a tiny ……………….. which points in ……………….. direction.
Answer
Answer: magnet; north-south
Question 9.
When we bring a ……………….. close to the needle, it gets ………………..
Answer
Answer: magnet; deflected
Question 10.
There is a maximum limit on the ……………….. which can safely flow through a ………………..
Answer
Answer: current; circuit
Question 11.
Our body is a ……………….. of electricity.
Answer
Answer: conductor
Question 12.
An electric cell produces electricity due to ……………….. stored in it.
Answer
Answer: chemicals
III. True or False
Question 1.
A battery is a combination of cells in which positive terminals of both the cells are connected to one other.
Answer
Answer: False
Question 2.
The key or switch can be placed anywhere in an electrical circuit.
Answer
Answer: True
Question 3.
CFLs increase wastage of power.
Answer
Answer: False
Question 4.
The wires used for making electric circuits normally become hot.
Answer
Answer: False
Question 5.
A glowing electric bulb becomes warm.
Answer
Answer: True
Question 6.
When the circuit is closed, the electric current does not flow throughout the circuit.
Answer
Answer: False
Question 7.
In an open circuit, the electric current flows throughout the circuit.
Answer
Answer: False
Question 8.
An electromagnet is a temporary magnet.
Answer
Answer: True
Question 9.
An electric bulb gives only light.
Answer
Answer: False
Question 10.
The electromagnet weakens the cell quickly if left connected to it.
Answer
Answer: True
IV. Match the Following
| Column I | Column II |
| 1. Fuse wire | (a) Miniature circuit breaker |
| 2. Switch | (b) Incomplete circuit |
| 3. MCB | (c) Complete circuit |
| 4. CFL | (d) High melting point |
| 5. Open circuit | (e) Heating effect of current |
| 6. Closed circuit | (f) Turns the circuit ‘ON’ or ‘OFF’ |
| 7. Electric heater | (g) Indian Standard Institute |
| 8. Electric bell | (h) Low melting point |
| 9. Heating element | (i) Compact fluorescent lamps |
| 10. ISI | (j) Magnetic effect of current |
Answer
Answer:
| Column I | Column II |
| 1. Fuse wire | (h) Low melting point |
| 2. Switch | (f) Turns the circuit ‘ON’ or ‘OFF’ |
| 3. MCB | (a) Miniature circuit breaker |
| 4. CFL | (i) Compact fluorescent lamps |
| 5. Open circuit | (b) Incomplete circuit |
| 6. Closed circuit | (c) Complete circuit |
| 7. Electric heater | (e) Heating effect of current |
| 8. Electric bell | (j) Magnetic effect of current |
| 9. Heating element | (d) High melting point |
| 10. ISI | (g) Indian Standard Institute |
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