Physics - Study Mode
[#941] Electromagnetic waves are transverse in nature is evident by
Correct Answer
(B) Polarisation
Explanation
Solution: Electromagnetic waves are transverse in nature is evident by Polarisation.
[#942] Which of the following parts of the sunlight makes the solar cooker hot ?
Correct Answer
(C) Infra red
Explanation
Solution: Glass transmits visible light but blocks infrared thermal radiation from escaping. This amplifies the heat trapping effect. A solar cooker, or solar oven, is
a device which uses the energy of direct sunlight to heat food or drink to cook it or sterilize it. The vast majority of the solar cookers presently in use are relatively cheap, low-tech devices. Because they use no fuel and cost nothing to operate, many nonprofit organizations are promoting their use worldwide to help reduce fuel costs for low-income people, reduce air pollution and slow deforestation and desertification, caused by use of firewood for cooking. Solar cooking is a form of outdoor cooking and is often used in situations where minimal fuel consumption is important, or the danger of accidental fires is high.
[#943] In the atmosphere ultraviolet rays are absorbed by
Correct Answer
(A) Oxygen
Explanation
Solution: As sunlight passes through the atmosphere, all UVC and approximately 90% of UVB radiation is absorbed by ozone, water vapour, oxygen and carbon dioxide. UVA radiation is less affected by the atmosphere. Therefore, the UV radiation reaching the Earth's surface is largely composed of UVA with a small UVB component.
[#944] Energy of Ultraviolet rays is great than
Correct Answer
(A) Infrared rays
Explanation
Solution: The energy of ultraviolet radiation is greater than the energy of infrared radiation because the velocity of ultraviolet radition is greater than the velocity of infrared solution.
[#945] Choose the most appropriate answer: Natural radioactivity was discovered by
Correct Answer
(C) Henry Bacquerel
Explanation
Solution: Natural radioactivity was discovered by Henri Bacquerel.