Question

Number of images between two plane mirrors at 70 degrees

Answer 1

The formula to find the number of images (n) formed between two plane mirrors inclined at angle, begin mathsize 12px style straight theta end style between them is as follows:

begin mathsize 14px style Number space of space images space formed space equals space fraction numerator 360 space degree over denominator straight theta end fraction space minus space 1 end style

Substituting the different values of angles between two inclined mirrors we can tabulate the answer as follows:

 

Angle between the two mirrors (begin mathsize 12px style straight theta end style)

Number of images formed (n)

45 °

7

60 °

5

120 °

2

180 °

1

0 °

Infinite

Answer 2

Answer:

The number of images formed between two plane mirrors at 70 degrees is 5.

Explanation:

Given the angle between two plane mirrors is 70°.

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

$N=\frac{360^{o} }{\theta} -1$

$=\frac{360}{70} -1$

$=\frac{36}{7} -1$

$=5.14 -1=4.14$

If N is not an integer, then it is corrected to the next integer.  

Therefore, the number of images formed between two plane mirrors at 70 degrees is 5.