Raman is a student of class X. Raman's mother was making tea in an old electric kettle having metal case. She switched on the power supply to the electric kettle. When Raman's mother touched the metal case of working electric kettle unknowingly, she got a severe electric shock. Raman put off the main switch quickly. After removing the kettle plug from socket, Raman found that the connecting cord was torn where it touched the metal case of the kettle. He also found that though the red and black wires of connecting cord were firmly connected to the two lower terminals of the power plug but the green wire of cord was not connected to the upper terminal of the plug. Raman replaced the torn connecting cord and also connected the three wires fo cord firmly to the power plug terminals.
(a) Why did Raman put off the main switch quickly ?
(b) What name is given to (i) red wire (ii) black wire, and (iii) green wire, of the connecting cord ?
(c) Which wire, red, black or green, touched the metal case of electric kettle when Raman's mother got electric shock ?
(d) Which safety device was not working in electric kettle circuit which could have prevented the electric shock ?
(e) What values are displayed by Raman in this incident ?

Explanation

(a) Raman put off the main switch to cut off the electricity supply to faulty electric kettle so as to save his mother.
(b) (i) Red wire is live wire (ii) Black wire is neutral wire, and (iii) Green wire is earth wire.
(c) Red wire (or live wire) which is at a high potential of 220 volts was touching the metal case of electric kettle.
(d) Earth wire.
(e) The values displayed by Raman are (i) Presence of mind (in putting off the main switch) (ii) Concern for mother (to save her life) (iii) Knowledge of household electric wiring, and (iv) Application of knowledge (in daily life situations).