(1) A bulb of 40 W is producing a light with 80% efficiency. Then the number of photons emitted in 20 seconds are (1eV = 1.6 X 10-19 J, hc = 12400 eV Ao)​ :-​(a) 2 X 1018(b) 1018(c) 1021(d) 2 X 1021​ (2) In a certain electronic transition in the Hydrogen atom from an initial state (1) to a final state (2), the difference in the orbital radius (r1 - r2) is 24 times the first Bohr radius. The transition is :-(a) 5 to 1(b) 25 to 1(c) 8 to 3(d) 6 to 5

Hemang Thakur , 10 Years ago

Grade 10