The minimum length of a plane mirror to see the entire full-length ima...
To understand why the correct answer is option 'C', let's analyze each option one by one.
a) When the bottom edge of the mirror is kept h/2 above the floor:
In this case, the top edge of the mirror will be at a height of h/2 + h/2 = h above the floor. Therefore, the mirror height is h, which is equal to the height of the person. So, the person will be able to see their entire full-length image.
b) When the bottom edge of the mirror is kept (h)/2 above the floor:
In this case, the top edge of the mirror will be at a height of (h/2 + h)/2 = 3h/4 above the floor. Therefore, the mirror height is h/4, which is less than the height of the person. So, the person will not be able to see their entire full-length image.
c) When the bottom edge of the mirror is kept (h)/2 above the floor:
In this case, the top edge of the mirror will be at a height of (h/2 + h/2)/2 = h/2 above the floor. Therefore, the mirror height is h/2, which is equal to half the height of the person. So, the person will be able to see their entire full-length image.
d) When the center of the mirror is at the same height as the center of the person:
In this case, the top edge of the mirror will be at a height of h/2 above the floor. Therefore, the mirror height is h/2, which is equal to half the height of the person. So, the person will be able to see their entire full-length image.
Based on the analysis above, option 'C' is the correct answer because when the bottom edge of the mirror is kept (h)/2 above the floor, the mirror height is h/2, which is equal to half the height of the person. Thus, the person will be able to see their entire full-length image.