Vaibhav had gone to his uncle's home in a foreign country where the domestic electric supply is D.C. (Direct Current). An electrician was working in his uncle's kitchen who was trying to find out the location of electric wiring in a particular wall for further electrical work. Failing to do so, the electrician recommended the breaking of substantial portion of the kitchen wall. Vaibhav told his uncle that he could locate the position of current-carrying wires in the kitchen wall without breaking the kitchen wall. In order to do this, Vaibhav purchased a small device from the market and moved it slowly over the whole kitchen wall. After about ten minutes, Vaibhav could locate the position of all the current-carrying wires in this kitchen wall. His uncle was happy that now only a small portion of the kitchen wall will have to be dismantled.
(a) What was the small device purchased by Vaibhav ?
(b) What was noticed by Vaibhav when this device was moved slowly over the current-carrying wires embedded in the wall ?
(c) What name was given to the effect which helped Vaibhav to locate the concealed current-carrying wires in the wall ?
Name the scientist who discovered the above effect.
(e) What values are shown by Vaibhav in this episode ?

Explanation

(a) Vaibhav purchased a plotting compass.
(b) When Vaibhav moved the plotting compass over the wall slowly, the compass needle was deflected from its usual north-south position whenever compass came over the current-carrying wires.
(c) Magnetic effect of electric current.
(d) Oersted.
(e) The values shown by Vaibhav are (i) Knowledge of scientific facts (that even a concealed current-carrying wire in a wall can create magnetic field around it and deflect compass needle), and (ii) Application of knowledge in everyday situations.