Test: Ray Optics - 1

The image in a plane mirror forms virtual and erect image and appears to be as far behind the mirror as the object is in front of the mirror. A diverging lens or a convex mirror forms a virtual image.A virtual image is produced by a concave mirror when the object is placed inside the focal length of the mirror.

Angle of reflection is the angle between a reflected ray and the normal drawn at the point of incidence to a reflecting surface.

When the object is placed at the center of curvature, the image is formed at the center of curvature and we know that the relation between radius of curvature and focal length is R= 2F ( R is used to show radius of curvature And F is the focal length ) if you will notice the its ray diagram then u could see that radius of curvature is always twice of Focal length.

The size of the image will  be 2.0 cm.
V=U(given)
m=-v/u
m= - 1
m=h`/h
-1=h`/2
h`=-2
h=2cm

For spherical mirrors,

m = - v/u

‘m’ is negative when both ‘v’ and ‘u’ have negative values. That is both object and image are on the same side.

So, the correct option is d. The image is inverted, since, it is real.

Option ( a) is the correct answer. As the object is always placed on the left side of the mirror and according to the sign convention, it has negative value for 'so axis.

Therefore, spherical mirrors have only one reflecting surface and it will be negative only.

The relation f = R/2 is applicable only for mirrors. For lenses, you have to use the lens makers formula.

An incident ray which passes through the centre of curvature C of the mirror is reflected back along it's own path ( since it is normally incident on the mirror) .

A convex mirror never forms an image larger than the original object, whereas a concave mirror can form an image larger than the object between the centre of curvature and the point of focus.

The light ray bends towards the normal as it travels from a rarer medium of air to a denser medium of water, under goes refraction. Refraction is due to change in the speed of light as it enters from one transparent medium to another. The speed of light increases in rarer medium and decreases in denser medium.

Refractive index, also called index of refraction, measure  of the bending of a ray of light when passing from one medium into another. As per Snell's law and the given information ;

According to sign convention distances and points are given their positive or negative sign on the basis of direction of propagation of incident Ray and the focus of both convex mirror and lens are in the front of propagating incident Ray of light so it is taken as positive

A virtual image of an object is formed by a convex lens only when the object is placed between the lens and the focus. Therefore, the focal length of the lens should be greater than the distance of the object from the lens. 

Because concave  lens always produce an
Image which is always erect, diminished and virtual.
 

Most of the refraction for the light rays entering the eye occurs at the outer surface of the cornea. 

The inability among the elderly to see near objects clearly because of the weakening of the ciliary muscles is called presbyopia. The focusing power of the eye lens decreases with age.