Uses of Electromagnetic Waves MCQs
Uses of Electromagnetic Waves MCQs
Class: 12 | Subject: Physics
Section: 5 – Electromagnetic Waves
Topic: Uses of Electromagnetic Waves
Based on: CBSE Board Examination Pattern
Section: 5 – Electromagnetic Waves
Topic: Uses of Electromagnetic Waves
Based on: CBSE Board Examination Pattern
Instructions: These Multiple Choice Questions (MCQs) are designed strictly as per the NCERT syllabus, making them ideal for CBSE Class 12 Board Examination preparation.
1. Radio waves are primarily used for:
Answer: B
Radio waves have long wavelengths and can diffract around obstacles, making them ideal for broadcasting and communication.
Radio waves have long wavelengths and can diffract around obstacles, making them ideal for broadcasting and communication.
2. Microwaves are used in microwave ovens because they:
Answer: B
Microwaves cause water molecules to vibrate, producing heat and cooking food.
Microwaves cause water molecules to vibrate, producing heat and cooking food.
3. Infrared radiation is widely used in:
Answer: A
Infrared detects heat emitted by objects → useful in night vision and thermal imaging.
Infrared detects heat emitted by objects → useful in night vision and thermal imaging.
4. Visible light is used in:
Answer: D
Visible light enables sight, photography, microscopes, telescopes, etc.
Visible light enables sight, photography, microscopes, telescopes, etc.
5. Ultraviolet rays are used for:
Answer: A
UV rays kill bacteria and are used for water purification and medical sterilization.
UV rays kill bacteria and are used for water purification and medical sterilization.
6. X-rays are commonly used in:
Answer: B
X-rays penetrate soft tissues and help detect bone fractures and internal injuries.
X-rays penetrate soft tissues and help detect bone fractures and internal injuries.
7. Gamma rays are used in:
Answer: A
Gamma rays destroy cancerous cells in radiotherapy.
Gamma rays destroy cancerous cells in radiotherapy.
8. Radar systems use:
Answer: B
Microwaves reflect strongly from aircraft and ships → radar detection.
Microwaves reflect strongly from aircraft and ships → radar detection.
9. Optical fibre communication uses:
Answer: B
Light signals transmit data via total internal reflection.
Light signals transmit data via total internal reflection.
10. Remote controls operate using:
Answer: A
Infrared LEDs transmit signals.
Infrared LEDs transmit signals.
11. Satellite communication uses:
Answer: A
Low atmospheric absorption.
Low atmospheric absorption.
12. Heat lamps use:
Answer: A
Infrared produces heating effect.
Infrared produces heating effect.
13. Airport security scanners use:
Answer: A
Detect hidden objects.
Detect hidden objects.
14. Photosynthesis uses:
Answer: A
Chlorophyll absorbs visible light.
Chlorophyll absorbs visible light.
15. TV broadcasting uses:
Answer: A
Long-distance signal transmission.
Long-distance signal transmission.
16. MRI uses:
Answer: A
Radio frequency pulses.
Radio frequency pulses.
17. Sun tanning is caused by:
Answer: B
UV stimulates melanin production.
UV stimulates melanin production.
18. Wireless internet uses:
Answer: A
Wi-Fi operates in microwave bands.
Wi-Fi operates in microwave bands.
19. Industrial radiography uses:
Answer: A
Detects cracks in metals.
Detects cracks in metals.
20. Germicidal lamps emit:
Answer: A
UV-C radiation kills microorganisms.
UV-C radiation kills microorganisms.
