Question
- Why are infra-red waves often called heat waves? Explain.
- What do you understand by the statement, ‘‘Electromagnetic waves transport momentum’’?
✓
Answer
- Infrared waves are prdocued by vibration of atoms of molecules which increases the temperature due which they are also the cause of heat energy.
- Electromagnetic waves also show particle nature, i.e., they aslo behave as a matter according to Planks Quantum theory, So, they also possess some momentum and they can also change momentum.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
Answer the following questions:
- Optical and radio telescopes are built on the ground while X-ray astronomy is possible only from satellites orbiting the Earth. Why?
- The small ozone layer on top of the stratosphere is crucial for human survival. Why ?
Monochromatic light of frequency $6.0 \times 10^{14} Hz$ is produced by a laser. The power emitted is $2.0 \times 10^{-3} W$. (a) What is the energy of a photon in the light beam? (b) How many photons per second, on an average, are emitted by the source?
→Verify that the units weber and volt-second are the same.
Explain about super conductor materials with respect to their magnetic properties.
Discuss sign convention of distance for reflection by spherical mirror and refraction by spherical lens.
What is doping ? - Explain.
In measuring time period of a pendulum, it is advised to measure the time between consecutive passage through the mean position in the same direction. This is said to result in better accuracy than measuring time between consecutive passage through an extreme position. Explain.
a. An electron moving horizontally with a velocity of $4 \times 10^4 m / s$ enters a region of uniform magnetic field of $10^{-5} T$ acting vertically upward as shown in the figure. Draw its trajectory and find out the time it takes to
b. A straight wire of mass 200 g and length 1.5 m carries a current of 2 A. It is suspended in mid air by a uniform magnetic field B. What is the magnitude of the magnetic field?
→b. A straight wire of mass 200 g and length 1.5 m carries a current of 2 A. It is suspended in mid air by a uniform magnetic field B. What is the magnitude of the magnetic field?
Find the maximum Coulomb force that can act on the electron due to the nucleus in a hydrogen atom.
Find the maximum angle of refraction when a light ray is refracted from glass $(\mu=1.50)$ to air.
→