Instrument measuring humidity: MCQ with Answer and Explanation

Explanation:
Steel has high retentivity, retains magnetism, used for permanent magnets. Soft iron has low retentivity, used for electromagnet core (temporary). Alnico, ferrites also used.

Explanation:
Fuse must be in live (phase) wire so that appliance is isolated when fuse blows.

Explanation:
a ∝ -x; magnitude maximum when |x| maximum (extremes). At mean position x=0 ⇒ a=0. Velocity maximum at mean position. Memory aid: 'SHM: a max at extremes, v max at center'. Oscillation concept frequently tested in competitive exams to verify SHM characteristics understanding.