$A$ boy of height $1.5\,m$ with his eye level at $1.4\,m$ stands before a plane mirror of length $0.75\,m$ fixed on the wall. The height of the lower edge of the mirror above the floor is $0.8\,m$. Which of the following is true?

$A$ plane mirror reflecting a ray of incident light is rotated through an angle $\theta$ about an axis through the point of incidence in the plane of the mirror perpendicular to the plane of incidence,then

An object is at a distance of $0.5 \ m$ in front of a plane mirror. The distance between the object and its image is ..... $m$.

$A$ ray reflected successively from two plane mirrors inclined at a certain angle undergoes a deviation of $300^o$. The number of observable images is:

Assertion : If the angle between the two plane mirrors is $72^o$ and the object is asymmetrically placed between the two mirrors,then $5$ images of the object will be formed.
Reason : For a given system of mirrors,the total number of images formed due to successive reflection is equal to either $\frac{360^o}{\theta}$ or $\frac{360^o}{\theta} - 1$ accordingly as $\frac{360^o}{\theta}$ is odd or even respectively.

If $\hat{n}_1, \hat{n}_2$ and $\hat{t}$ represent unit vectors along the incident ray, reflected ray, and normal to the surface respectively, then: