Question

Q. What part of second is called nanosecond?
Q. _________ is the phenomenon by which incident ray of light is sent back to same medium after falling on a smooth surface.
Q. Read the statements and choose the correct option.
1. Moon is a luminous sources of light.
2. A glow worm is a natural source of light.

A. only i is true
B. only ii is true
C. Both are true
Both are false

Q. _____image is formed by a pinhole camera.

Answer 1

Dear Student,

$$\begin{gathered} 1nanosecond=\frac{1}{{10}^9}second={10}^{-9}second. \\ 2-Aluminousobjectisonethatgivesofflight.Inotherwords,itglows(orshines)ofitsownaccord. \\ Tobeabletoglow,theobjectmusthaveitsownsourceofenergy.Hence \\ moonisnotalumiousobjectbecauseitappearbrightduelightofsun. \\ Aglowwormisanaturalsourceoflight. \\ OptionBiscoorect. \\ 3-APinholeCameraisasimplecamerawithoutalensbutwithatiny \\ aperture,apinhole–effectivelyalight-proofboxwithasmallholeinoneside. \\ Lightfromascenepassesthroughtheapertureandprojectsan \\ invertedimageontheoppositesideofthebox \end{gathered}$$

Regards.