Radio Waves Microwaves Infrared Visible UV Xrays Gamma Rays - UNSOLVED PRACTICE SET
Chapter: Electromagnetic Waves | Topic: Radio Waves Microwaves Infrared Visible UV Xrays Gamma Rays
RADIO WAVES MICROWAVES INFRARED VISIBLE UV XRAYS GAMMA RAYS - UNSOLVED PRACTICE SET
Topic: Radio Waves Microwaves Infrared Visible UV Xrays Gamma Rays
Multiple Choice Questions
Q1. Radio waves are produced by:
- Atomic nuclei
- Accelerated charges in antennas
- Inner shell electrons
- Nuclear transitions
Q2. Microwaves are used in:
- Medical imaging
- Radar systems and microwave ovens
- Sterilizing medical equipment
- Night vision cameras
Q3. Infrared radiation is primarily associated with:
- Nuclear reactions
- Thermal radiation from hot bodies
- Electronic transitions in atoms
- Radioactive decay
Q4. X-rays are produced when:
- Electrons jump between outer energy levels
- Fast-moving electrons are suddenly stopped by a metal target
- Nuclei undergo radioactive decay
- Molecules vibrate
Q5. Gamma rays have the highest penetrating power because they:
- Have the longest wavelength
- Have the highest frequency and energy
- Are produced by the Sun
- Travel slower than other EM waves
Q6. Ultraviolet radiation is responsible for:
- Heating food in microwave ovens
- Tanning of skin and causing sunburn
- Radio communication
- Medical X-ray imaging
Short Answer Questions
Q7. How are radio waves produced? State two methods of generating radio waves.
Q8. What are microwaves? Name two sources and two applications of microwaves.
Q9. Why do we feel warmth when standing near a fire or an electric heater? Which electromagnetic radiation is responsible?
Q10. How are X-rays produced? What is the difference between characteristic X-rays and continuous X-rays?
Q11. Compare the penetrating power of ultraviolet radiation, X-rays, and gamma rays. Arrange them in order of increasing penetrating ability.
Q12. Why can't our eyes see infrared or ultraviolet radiation, even though they are present all around us?
Long Answer Questions
Q13. Describe the production, properties, and uses of radio waves and microwaves. Explain the difference between them in terms of wavelength and how they are generated.
Q14. Explain how X-rays are produced in an X-ray tube. Describe the continuous and characteristic X-ray spectra and the factors that affect the quality and intensity of X-rays.
Q15. Compare gamma rays and X-rays in terms of their origin, properties, and applications. Why are gamma rays more dangerous to living organisms than X-rays?
Numerical & Application-Based Problems
Q16. Calculate the frequency and energy of photons for the following electromagnetic waves:
(a) Radio waves with wavelength 500 m
(b) Microwaves with wavelength 2 cm
(c) Visible light with wavelength 600 nm
(d) X-rays with wavelength 0.1 nm
(e) Gamma rays with wavelength 10โปยนยฒ m
Q17. An X-ray machine operates at a voltage of 50 kV.
(a) Calculate the maximum energy of the X-ray photons produced.
(b) Calculate the minimum wavelength of the X-rays emitted (Duane-Hunt law).
(c) Explain why this is called the 'cut-off' wavelength.
Q18. In your daily life in India, you encounter many types of electromagnetic waves:
(a) Your FM radio tunes to 91.1 MHz (Radio City). Calculate the wavelength and identify the region of the EM spectrum.
(b) Your microwave oven operates at 2.45 GHz. Calculate the wavelength and explain why this frequency is particularly effective for heating food.
(c) During a medical check-up, a chest X-ray is taken. The X-rays have a wavelength of about 0.1 nm. Calculate their frequency and compare their photon energy with that of visible light (ฮป = 500 nm). Why are X-rays dangerous while visible light is safe?
(d) Your mobile phone tower emits radiation in the microwave region. A concerned neighbor claims that this radiation is as dangerous as gamma rays from a nuclear reactor. Use your knowledge of the EM spectrum to evaluate this claim and explain the actual risks (if any) of mobile phone radiation.