If an object is placed symmetrically between two plane mirrors, inclin

1.	If an object is placed symmetrically between two plane mirrors, inclined at an angle of 72°, then total number of images formed is:A. 5B. 4 C. 2 D. infinite
Answer» The number of images formed if two plane mirrors are kept at an angle θ is given by, \(\frac{360^o}{\theta}\,if\,\frac{360^o}{\theta}\) is odd and it is given by \(\frac{360^o}{\theta}\,-1\,if\,\frac{360^o}{\theta}\)is even. For \(\theta\)= 72^o, number of image is \(\frac{360^o}{72^o}\,=\,5\) as \(\frac{360^o}{72^o}\,=\,5\) is an odd number.

If an object is placed symmetrically between two plane mirrors, inclined at an angle of 72°, then total number of images formed is:A. 5B. 4 C. 2 D. infinite

Answer»

The number of images formed if two plane mirrors are kept at an angle θ is given by,

\(\frac{360^o}{\theta}\,if\,\frac{360^o}{\theta}\) is odd and it is given by \(\frac{360^o}{\theta}\,-1\,if\,\frac{360^o}{\theta}\)is even.

For \(\theta\)= 72^o, number of image is \(\frac{360^o}{72^o}\,=\,5\) as \(\frac{360^o}{72^o}\,=\,5\) is an odd number.