Tag: uses of plane mirror

Quizzes (0) Questions (19)

Questions Related to uses of plane mirror

Multiple choice evs magic with mirrors kaleidoscope uses of plane mirror reflected light can be reflected again

When does the tumbling of coloured objects presents varying colours and patterns in kaleidoscope?

  1. When kaleidoscope tube is stood erect
  2. When kaleidoscope tube is tilted at $180^0$

  3. When kaleidoscope tube is rotated

  4. When kaleidoscope tube is inverted
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When kaleidoscope tube is rotated then it forms different varying patterns and colours.

Multiple choice evs magic with mirrors kaleidoscope uses of plane mirror reflected light can be reflected again

What is Kaleidoscope?

  1. A cylinder with mirrors containing loose colored objects such as beads, pebbles, and bits of glass

  2. A cylinder with mirrors

  3. A cylinder containing loose colored objects such as beads, pebbles, and bits of glass

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

$Answer:-$ A option

A kaleidoscope is an optical instrument, typically a cylinder with mirrors containing loose, colored objects such as beads or pebbles and bits of glass. As the viewer looks into one end, lightening the other end creates a colorful pattern, due to repeated reflection in the mirrors.

Multiple choice evs magic with mirrors kaleidoscope uses of plane mirror reflected light can be reflected again

An object is kept between two plane mirrors inclined at an angle $120$ from each other; calculate the number of images which are formed if the object is not on the bisector/on the bisector $3$

  1. $\displaystyle \frac {3}{3}$
  2. $\displaystyle \frac {3}{2}$
  3. $\displaystyle \frac {2}{2}$
  4. $\displaystyle \frac {2}{3}$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Given: An object is kept between two plane mirrors inclined at an angle 120 from each other

To find the ratio of number of images which are formed if the object is not on the bisector and on the bisector
Solution:
If there are two plane mirrors inclined to each other at an angle $\theta$, the number of images of a point object formed are determined as follows:

If $\left(\dfrac {360^\circ}\theta\right)$ is odd integer (say $m$) number of images formed
$n = m$, if the object is not on the bisector of mirrors
$n = (m – 1)$, if the object is on the bisector of mirrors.

So, when $\theta=120^\circ$, we get
$m=\dfrac {360}{120}=3$
So,
$\dfrac {\text{ number of images which are formed if the object is not on the bisector}}{\text{ number of images which are formed if the object is on the bisector}}=\dfrac {3}{3-1}=\dfrac 32$