Statement I: All hot bodies radiate heat. ​

Statement II: When heat radiation falls on an object, a part of it is reflected, a part is absorbed, and a part may be transmitted.

Q. When radiated heat falls on an object, a part of it is reflected, a part of it is absorbed and a part may be transmitted. The temperature of the object increases due to the

जब एक वस्तु पर विकिरणित ऊष्मा आपतित होती है, तब इसका एक भाग परावर्तित होता है, एक भाग अवशोषित होता है तथा एक भाग पारगमित हो सकता है। वस्तु का ताप किसके कारण बढ़ता है?

Q. Fill in the blanks, according to the Greenhouse effect.
$1.$ Clouds and gases reflect about $\dots a\dots$ of the incoming solar radiation, and absorb some of it but almost $\dots b\dots$ of incoming solar radiation falls on Earth’s surface heating it, while a small proportion is reflected back.
$2.$ Earth’s surface re-emits heat in the form of $\dots c\dots$ radiation but part of this does not escape into space as atmospheric gases absorb a major fraction of it.

Q. In the following, which statement is correct :
a) A hot body emits hot radiations only.
b) A cold body absorbs the radiations only.
c) A cold body emits cold radiations only.
d) All the bodies emit and absorb radiations simultaneously.

Q. Statement 1: All hot bodies radiate heat.
Statement 2: Medium is required for transfer of heat by the process of radiation.

Q. In a completely opaque medium, if 50% of the incident monochromatic radiation is absorbed, then which one of the following statements is correct?

(P) 50% of the incident radiation is reflected
(Q) 25% of the incident
radiation is reflected
(R) 25% of the incident radiation is
transmitted
(S) No incident radiation is transmitted