If voltage across a bulb rated 220 volt-100 Watt drops by 2.5% of its rated value

If Voltage Across A Bulb Rated 220 Volt100 Watt Drops Physics Question

If voltage across a bulb rated 220 volt-100 Watt drops by 2.5% of its rated value, the percentage of the rated value by which the power would decrease is:

Options

(a) 20%
(b) 2.50%
(c) 5%
(d) 10%

Correct Answer:

5%

Explanation:

Resistance of bulb is constant
P = V² / R
∆p / p = 2∆V / V + ∆R / R
∆p / P = 2 x 2.5 + 0 = 5%

Related Questions:

  1. The ratio of the numerical value of the average velocity and average speed
  2. A photon of energy 10.2 eV collide inelastically with hydrogen atom in ground state
  3. When volume of a system is increased two times and temperature is decreased
  4. The potential energy of a system increases if work is done
  5. If the image formed by a convex mirror of focal length 30 cm is a quarter of the size

Topics: Current Electricity (136)
Subject: Physics (2479)

Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score

18000+ students are using NEETLab to improve their score. What about you?

Solve Previous Year MCQs, Mock Tests, Topicwise Practice Tests, Identify Weak Topics, Formula Flash cards and much more is available in NEETLab Android App to improve your NEET score.

NEETLab Mobile App

Share this page with your friends

Be the first to comment

Leave a Reply

Your email address will not be published.


*