Electric Current and Its Effects MCQs
Electric Current and Its Effects – MCQs with Answers & Explanations
Class: CBSE Class 7
Subject: Science
Section: Electricity & Magnetism
Topic: Electric Current and Its Effects
Board: CBSE Board Examination
Subject: Science
Section: Electricity & Magnetism
Topic: Electric Current and Its Effects
Board: CBSE Board Examination
These Multiple Choice Questions (MCQs) are designed strictly as per the NCERT syllabus, making them ideal for CBSE Class 7 Science examination preparation. Each question includes detailed explanations for better concept clarity.
1. The heating effect of electric current is used in:
Answer: b) Electric iron
Electric iron works on the heating effect of current where electrical energy converts into heat energy.
Electric iron works on the heating effect of current where electrical energy converts into heat energy.
2. A fuse wire is made of:
Answer: b) Low melting point metal
Fuse melts quickly when excess current flows, protecting appliances.
Fuse melts quickly when excess current flows, protecting appliances.
3. Which effect of current makes a bulb glow?
Answer: b) Heating
The filament becomes hot and emits light due to heating effect.
The filament becomes hot and emits light due to heating effect.
4. The device that protects circuits from overcurrent is:
Answer: b) Fuse
Fuse breaks the circuit when current exceeds safe limit.
Fuse breaks the circuit when current exceeds safe limit.
5. LED stands for:
Answer: a) Light Emitting Diode
LED produces light with very little heat and high efficiency.
LED produces light with very little heat and high efficiency.
6. Magnetic effect of current is used in:
Answer: a) Electric bell
Electric bell uses electromagnets formed by current.
Electric bell uses electromagnets formed by current.
7. An electromagnet works when:
Answer: a) Current flows
Magnetic field is produced only when current passes.
Magnetic field is produced only when current passes.
8. Filament of bulb is made of:
Answer: c) Tungsten
Tungsten has very high melting point.
Tungsten has very high melting point.
9. Overheating of wires can cause:
Answer: d) All of these
Excess current produces heat leading to hazards.
Excess current produces heat leading to hazards.
10. Device converting electrical energy to heat:
Answer: a) Heater
Heaters use heating effect of current.
Heaters use heating effect of current.
11. Electromagnet core is usually made of:
Answer: b) Soft iron
Soft iron magnetizes and demagnetizes easily.
Soft iron magnetizes and demagnetizes easily.
12. SI unit of current:
Answer: b) Ampere
Current is measured in ampere.
Current is measured in ampere.
13. Thin fuse wire melts due to:
Answer: b) Heating
Excess heat melts the fuse.
Excess heat melts the fuse.
14. Electric bell has:
Answer: a) Electromagnet
15. Which is safest lighting device?
Answer: b) LED
Consumes less energy and produces less heat.
Consumes less energy and produces less heat.
16. Heating effect depends on:
Answer: d) All
17. Coil carrying current behaves like:
Answer: b) Magnet
18. Device using magnetic effect:
Answer: d) All
19. Excess current flow is called:
Answer: a) Overloading
20. Fuse is connected in:
Answer: a) Series
So entire circuit breaks when fuse melts.
So entire circuit breaks when fuse melts.
