भारतीय घरेलू बिजली आपूर्ति में लाल जीवित तार (live wire) और काले उदासीन तार (neutral wire) के बीच r.m.s. विभवांतर कितना होता है?

The main purpose of the earth wire in a domestic electric circuit is:

Which of the following statements is/are true for a standard domestic electric circuit? (i) All the appliances are connected in parallel. (ii) The live wire in the domestic circuit has green insulation on it. (iii) A fuse connected to the circuit allows excessive current to pass through the appliances. (iv) The neutral wire in the domestic circuits has black insulation on it.