Question

A rubber is rubbed with a woollen carpet is found to acquire a positive chargeof 8*10^-7C.estimate the number of electrons transferred from woollen carpet to rubber sheet

Answer 1

Answer:

(a) We know, electric charge of a body is quantized

e.g., Q = ne

Given, Q = 3 × 10⁻⁷C

e = 1.6 × 10⁻¹⁹ C [ charge on each electron ]

n = Q/e = 3 × 10⁻⁷/1.6 × 10⁻¹⁹

= 3/1.6 × 1.875 × 10¹²

So, 1.875 × 10¹² electrons have transferred from wool to polythene .

(b) yes , as you know, mass of electron = 9.1 × 10⁻³¹ kg

∴ transfer of mass = number of electron × mass of each electron

= 1.875 × 10¹² × 9.1 × 10⁻³¹

= 1.71 × 10⁻¹⁸ Kg has transferred from whool to polythene.