Which of the following has highest specific heat capacity? MCQ with Answer and Explanation

Explanation:
Soft iron has high permeability, low retentivity, easily magnetized and demagnetized.

Explanation:
Astigmatism: cornea curvature not spherical, different focal lengths in different planes. Corrected by cylindrical lens which has different powers in perpendicular axes. Not simple spherical lens.

Explanation:
Barometer measures atmospheric pressure. Mercury barometer (Torricelli) standard. Aneroid barometer. Manometer measures pressure difference. Hydrometer density. Lactometer milk purity.