The mass of a proton is about _____ times the mass of an electron. MCQ with Answer and Explanation

Explanation:
Heat required Q = m c ΔT = 5 × 4200 × 20 = 420,000 J. Power 2000 W, time t = Q/P = 420000/2000 = 210 s.

Explanation:
Telescope forms inverted, virtual image at infinity (or near point). For terrestrial, erecting lens makes erect.

Explanation:
An ammeter must have very low resistance so it does not alter the circuit current it is measuring. To convert a sensitive galvanometer into an ammeter, a very low resistance called a 'shunt' is connected in parallel to it. This diverts most of the current away from the delicate galvanometer coil while still allowing a proportional measurement.