A boy is trying to start a fire by focusing sunlight on a piece of paper using

A Boy Is Trying To Start A Fire By Focusing Physics Question

A boy is trying to start a fire by focusing sunlight on a piece of paper using an equiconvex lens of focal length 10 cm. The diameter of the sun is 1.39 x 10⁹ m and its mean distance from the earth is 1.5 x 10¹¹ m. What is the diameter of the Sun’s image on the paper?

Options

(a) 9.2 x 10⁻⁴ m
(b) 6.5 x 10⁻⁴ m
(c) 6.5 x 10⁻⁵ m
(d) 12.4 x 10⁻⁴ m

Correct Answer:

9.2 x 10⁻⁴ m

Explanation:

We have, | v /u | = size of image / size of object
or, size of image = | v / u | x size of object
= (10⁻¹ / 1.5 x 10¹¹) x (1.39 x 10⁹)
= 0.92 x 10⁻³ m
Diameter of the sun’s image = 9.2 x 10⁻⁴ m

Related Questions:

  1. The condition under which a microwave oven heats up a food item containing
  2. The excess pressure inside one soap bubble is three times that inside a second soap bubble
  3. A circuit contains an ammeter, a battery of 30 V and a resistance 40.8 ohm
  4. The ratio of the acceleration for a solid sphere(mass m and radius R)rolling down
  5. The electirc field in a certain region is acting radially outward and is given by E=Ar.

Topics: Ray Optics (94)
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Your email address will not be published.


*