The electric field intensity produced by the radiations coming from 100 W bulb at a 3 m distance is E. The electric field intensity produced by the radiations coming from 50 W bulb at the same distance is a) E/2 b) 2E c) E/√2 d) √2E
Correct option is A) Power of bulb=100W Intensity of Electric field at a distance 3m is E. The electric field intensity is given by: E=AP ⇒E=πr2100=π×32100=9π100watt/m2 Similarly, E at a distance of 3m produced by 50W bulb is: ⇒E1=πr250watt/m2=9π50watt/m2 E1E=9π100÷9π50 ⇒E1E=9π100×509π=2 ⇒E1=2E
