Class 7 Science Chapter 10 MCQ Electric Current and its Effects
MCQ on Electric Current and its Effects Class 7
I. Multiple Choice Questions (1 Mark)
Select and write the most appropriate option out of the four options given
Question 1.
The symbol used for a switch in ‘ON’ condition is
Answer:
(D)
Question 2.
An electric bulb does not glow in a circuit if
A) there is a broken circuit.
B) there is no conducting material.
C) there is no source of electric current.
D) all of these
Answer:
D) all of these
Question 3.
A switch or a key in a circuit can be placed
A) on the right side of the battery only
B) on the left side of the battery only
C) near the positive terminal of the bulb only
D) anywhere in the circuit.
Answer:
D) anywhere in the circuit.
Question 4.
In an electric circuit, the current starts from
A) the positive terminals of the battery
B) the negative terminal of the battery
C) either of the terminals of the battery
D) none of the terminals of the battery
Answer:
A) the positive terminals of the battery
Question 5.
The electric fuse works on the phenomenon of
A) heating effect of current
B) chemical effect of current
C) magnetic effect of current
d) none of these
Answer:
A) heating effect of current
Question 6.
……….. mark is necessary on electric appliances.
A) FICC
B) ISI
C) KSK
D) AGMARK
Answer:
B) ISI
Question 7.
The coil of wire contained in heater or geyser is known as
A) circuit
B) component
C) spring
D) element.
Answer:
D) element.
Question 8.
Mark out the correct statement.
A) Fuses and MCBs are safety devices.
B) Fuses are safety devices but MCBS are not.
C) MCBs are safety devices but fuses are not.
D) Neither fuses nor MCBs are safety devices.
Answer:
A) Fuses and MCBs are safety devices.
Question 9.
Temporary magnets are made of
A) brass
B) soft iron
C) soil
D) lead.
Answer:
B) soft iron
Question 10.
Which of the following is a temporary magnet?
A) Electromagnet
B) Ring-shaped magnet
C) Bar magnet
D) Magnetite
Answer:
A) Electromagnet
Question 11.
When an iron rod is put inside a current-carrying wire, the strength of the electromagnet
A) remains same
B) decreases
C) increases
D) becomes zero.
Answer:
C) increases
Question 12.
Overloading is
A) putting more current across a wire than it can handle
B) touching of live wire with the earth wire
C) touching of neutral wire with the earth wire
D) touching of live wire with the neutral wire.
Answer:
A) putting more current across a wire than it can handle
Question 13.
Study the circuit shown here. Which switch if opened will cause the light bulb to stop glowing?
A) P
B) Q
C) R
D) S
Answer:
A) P
Question 14.
The bulb in the circuit given here does not glow. Which labelled part is responsible for this ?
A) 1
B) 2
C) 3
D) 4
Answer:
C) 3
Question 15.
Which of the following devices does not use an electromagnet?
A) Electric bell
B) Magnetic crane
C) Loudspeaker
D) Electrical iron
Answer:
D) Electrical iron
Question 16.
A light steel bar and a light iron bar are attracted to a magnet as shown. What will possibly happen when the magnet is removed?
A) The steel and iron bars repel each other.
B) Both steel and iron bars lose their magnetism.
C) Steel bar retains its magnetism and iron bar loses its magnetism.
D) Iron bar retains its magnetism and steel bar loses its magnetism.
Answer:
C) Steel bar retains its magnetism and iron bar loses its magnetism.
Question 17.
Which coil produces the strongest electromagnet for a given flow of current ?
A) A 10 cm coil with 100 turns
B) A 5 cm coil with 200 turns
C) A 10 cm coil with 200 turns
D) A 20 cm coil with 200 turns
Answer:
B) A 5 cm coil with 200 turns
II. Fill in the blanks
1. A battery is a combination of two or more …………
Answer: cells
2. In the symbol of an electric cell, the longer line represents the ………… terminal while the thicker and shorter line represents the …………
Answer: positive, negative
3. The thin wire inside a bulb is known as ………… terminal.
Answer: filament
4. The device that is used to prevent the flow of current in the circuit is called …………
Answer: switch
5. The heating coil of an electric geyser is made up of …………
Answer: nichrome
6. The full form of MCB is …………
Answer: miniature circuit breaker
7. The amount of heat produced will be increased if the amount of current flowing is………… in a circuit.
Answer: increased
8. Magnetic effect of current was discovered by …………
Answer: Hans christain oersted
9. The needle of a magnetic compass shows ………… when it is brought near a current carrying wire.
Answer: deflection
10. When an electric current flows through a wire, it behaves like a …………
Answer: magnet
11. Under normal conditions, a magnetic compass needle always rests in ………… direction.
Answer: North, South
12. Doctors use very small but strong ………… to remove iron dust from a patient’s eye.
Answer: electromagnets
13. If the amount of current passing through the coil of an electromagnet is decreased, the strength of the electromagnet will …………
Answer: decrease
14. A current-carrying coil of an insulated wire wrapped around a piece of iron is called an …………
Answer: electromagnet
15. Long and thin wires have ………… resistance than small and thick wires.
Answer: higher
16. Electric current flows where there is some difference in …………
Answer: potential
17. Electric cell : Button :: ………… : Bar
Answer: magnet
18. Nichrome has ………… resistivity and ………… melting point.
Answer: high, high
19. Mica is a ………… conductor of electricity but a ………… conductor of heat.
Answer: bad, good
20. The ………… the resistance, the greater is the current.
Answer: lower
21. The filament of an electric bulb has ………… melting point.
Answer: high
22. A ………… occurs when a broken or bare wire in a circuit touch another wire in the circuit.
Answer: short circuit
III. True Or False
1. A single cell is also known as battery.
Answer: False
2. Electric current flows from positive terminal to the negative terminal of a cell in an electric circuit.
Answer:
3. 
is the symbol of a battery.
Answer: False
4. Electric current flows in an open circuit.
Answer: False
5. A fuse is an application of chemical effect of current.
Answer: False
6. The amount of heat produced does not depend on the nature of material of the wire.
Answer: False
7. An ISI mark is necessary for electrical appliances.
Answer:
8. A compass needle shows deflection when it is brought near a bar magnet.
Answer: True
9. A compass needle always rests in North-South direction when the current is switched off.
Answer: True
10. A compass needle shows deflection even when electric current is not passing through the coil.
Answer: False
11. Flow of electric current in a circuit is opposite to the flow of electrons.
Answer: True
12. An electric door bell has a coil of wire wound on a soft iron core which is known as electromagnet.
Answer: True
13. The insulation on wifes ensures an interrupted passage of electric current
Answer: False
14. Heating effect of electric current is used in an electric bell.
Answer: False
15. CFLs consume less electricity than ordinary bulbs.
Answer: True
16. A switch can be placed anywhere in the circuit.
Answer: True
17. Resistance resists the flow of electrons in a conductor.
Answer: False
18. An MCB turns off automatically when current in a circuit exceeds the safe limit.
Answer: True
IV. Matching
| 1. Column – I | Column – II |
| A) The coil of wire used in a heater to get heat | i) Filament |
| B) Heating effect of current | ii) CFL |
| C) Magnetic effect of current | iii) Element |
| D) Made of alloy with low melting point | iv) Electromagnet |
| E) Consumes less energy than bulb | v) Fuse |
Answer:
| 1. Column – I | Column – II |
| A) The coil of wire used in a heater to get heat | iii) Element |
| B) Heating effect of current | i) Filament |
| C) Magnetic effect of current | iv) Electromagnet |
| D) Made of alloy with low melting point | v) Fuse |
| E) Consumes less energy than bulb | ii) CFL |