Flag Engineering Entrance Exams> Two electric bulbs whose resistances are ...
question mark

Two electric bulbs whose resistances are in the ratio of 1 : 2 are connected in parallel to a constant voltage source. The powers dissipated in them have the ratio a) 1 : 2 b) 1 : 1 c) 2 : 1 d) 1 : 4

Madhukar Anand , 12 Years ago
Grade
anser 2 Answers
Saurabh Koranglekar
576-474_a.PNG
Last Activity: 5 Years ago
Vikas TU
The equation for power in a resistance R, connected to a voltage V, is P = V^2/Rn. where Rn is the resistance of light bulb N.
Let R1 - resistance of Bulb 1 and R2 = resistance of Bulb 2. Since the bulbs are connected in parallel, then V1 = V2 = V. Given that R2 = 2٠R1, then P1 = V^2/R1, and P2 = V^2/(2٠R1). so the ratio of the power dissipated in the two bulbs is P1/P2 = (V^2/R1)/[V^2/(2٠R1)] = (2٠R1)/R1 = 2 (or 1/2, depending on which way you write the ratio).
 
Last Activity: 5 Years ago
star
LIVE ONLINE CLASSES

Prepraring for the competition made easy just by live online class.

tv

Full Live Access

material

Study Material

removal

Live Doubts Solving

assignment

Daily Class Assignments



question mark
Hello,
 
Can we learn and prepare for MHT-CET online ?
engineering entrance exams
1 Answer Available

Last Activity: 4 Years ago