Questions

Black  surfaces are good emitters of heat ( They are also good absorbers of heat). If the black surface is rough too, the emitting will be better. So (b) is the correct answer. Shining surfaces reflect back radiation. So if the black surface is also shining the effectiveness of emitting heat is lessened.

Astigmatism is a common vision condition that causes blurred vision. It occurs when the cornea is irregularly shaped or sometimes because of the curvature of the lens inside the eye.

Galloping inflation is also known as jumping inflation.

It refers to a type of inflation that occurs when the prices of goods and services increase at the two-digit or three-digit rate per annum.