|1 Crore+ students have signed up on EduRev. Have you?|
You are provided with a convex lens of F = 50 cm. To obtain a smaller inverted image, the distance of the object from the lens should be
Step 1: Determine if the focal length is positive or negative.
Step 2: Determine if the image distance is positive or negative.
Step 3: Use the equation
to calculate the distance of the object from the lens.
You are provided with a convex lens of focal length 20 cm. To obtain a real inverted and magnified image of an object, distance of object from lens must be
When the image formed by a convex lens, inverted and same size as the object, then the distance of the object from the lens is 2f (twice the focal length). Here,
Focal length, f = 20 cm
So, 2f = 2 × 20 cm
= 40 cm
Thus, the object should be placed at a distance of 40 cm in front of the convex lens.
The linear magnification of a convex lens
A convex mirror would always produce an erect image, and a concave mirror may produce an inverted or an erect image depending on the position of the object placed.
Thus, independent of the sign convention, the magnification of a convex mirror is always positive, but that of a concave mirror may be both positive or negative.
You have caught your left ear but it appears that you have caught your right ear, it means you are standing in front of a
The plane mirror shows lateral inversion. The left appears right and the right appears left. So if you touch your left ear with your right hand in front of a plane mirror it will be seen in the mirror that your right ear is touched with your left hand.
A child is standing in front of magic mirror. He finds the image of his head bigger, the middle portion of his body of the same size and that of legs smaller. The following is the order of combinations for the magic mirror from the top.
As image of head is bigger, the top portion of magic mirror must be concave. The middle portion appears to be of same size, therefore, middle portion of magic mirror must be plane. As image of his legs appear smaller, the bottom of magic mirror must be convex.
You are given water, mustard, oil glycerine and kerosene. In which of these media a ray of light incident obliquely at same angle would bend the most?
Refractive index for water, mustard oil, glycerine and kerosene are:
μw = 1.33
μm = 1.47
μg = 1.473
μk = 1.44
Since refractive index of glycerine is highest, ray bends the most in case of glycerine.
When a ray of light is incident (coming out) from a glass slab into the air, then the reflected ray will be
When light rays travelling through air enters glass slab, they get refracted and bend towards the normal. Now the direction of refracted ray changes again when it comes out of the glass slab into air. Since the ray of light I know travelling from denser medium to rarer medium, it bends away from the normal.
A full length image of a distant tall building can definitely be seen by using
We know that a convex mirror forms a virtual and smaller image irrespective of position of the object. So, a full length image of a distant tall building can definitely be seen by using a convex mirror.
Which of the following statement is true?
A beam of light is incident through the holes on side A and emerges out of the holes on the side B of the box as shown in the figure. Which of the following could be inside the box?
The power of a concave lens of focal length 2 m is
f = – 2 m = – 200 cm
Magnification produced by a rear view mirror fitted in which lens is
Convex mirrors are used in vehicles for rearview due to their wide field of view. And the convex mirror forms a virtual, erect and diminished image of the object. Therefore, magnification (m) produced by a rearview mirror fitted in vehicles is less than one.
In torches, search lights and headlights of vehicles, the bulb is placed
To create a parallel beam of light through which we can see further, the bulb in torches, search lights, and vehicle headlights is placed very close to the focus of the reflector.
Which of the following ray diagrams is correct for the ray of light incident on a concave mirror?
The ray of light incident on a concave mirror in a direction parallel to principal axis must pass through focus F on reflection from the mirror.
A virtual, erect and magnified image is formed by a convex lens of focal length 10 cm. The distance of object from the lens is
For a virtual, erect and magnified image, object lie between F and C.
If F = 10 cm, r = F/2 = 5 cm which is OC.