Reflection And ...

An object is initially at a distance of 500 cm from a plane mirror. If the mirror approaches the object at a speed of 2 cm/s, then after 6 seconds, the distance between the object and its image will be

The image formed by a convex mirror of a real object is larger than the object

A concave mirror of focal length 'f' produces an image 'm' times the size of the object. If the image is real, then the distance of the object from the mirror is

The height of an object is 7 cm and is placed 15 cm from the convex spherical mirror of radius 45 cm. The height of the image formed is

A ray of light is incident at 50° on the middle of one of the two mirrors arranged at an angle of 60° between them. The ray then touches the second mirror, gets reflected back to the first mirror, making an angle of incidence

A 4.5 cm long needle is placed 12 cm away from a convex mirror of focal length 15 cm. Give the location of the image and the magnification.

A ray of light enters from a rarer medium to a denser medium at an angle of incidence where the reflected and refracted rays make an angle of 90° with each other. The angles of reflection and refraction are r and r', respectively. The critical angle of the denser medium is

A transparent object is immersed in water. In order that the object becomes invisible, it should

The focal length of the objective and the eye piece of a microscope are 4 mm and 25 mm, respectively. If the final image is formed at infinity and the length of the tube is 16 cm, the magnifying power of microscope will be

An object is put at a distance of 5 cm from the first focus of a convex lens of focal length 10 cm. If a real image is formed, its distance from the lens will be

A point source of light S is placed at a distance L in front of the centre of a plane mirror PQ of width d. It is hung vertically on a wall as shown in the figure. A man walks in front of the mirror along a line parallel to the mirror at a distance 2L from it. The greatest distance over which he can see the image of the light source in the mirror is

An air bubble in a glass slab ( = 1.5) is 6 cm deep as viewed from one face and 4 cm deep as viewed from other face. The thickness of the glass slab is

A thin lens has focal length f and its aperture has diameter d. It forms an image of intensity I. Now, the central part of the aperture up to diameter (d/2) is blocked by an opaque paper. The focal length and the image intensity will change respectively to

A microscope has an objective of 5 mm focal length and eye-piece of 30 mm focal length and the distance between them is 150 mm. The magnification is

In cold countries, the phenomenon of looming (i.e. ship appears in the sky) takes place, because refractive index of air

The path of a ray of light in different media of the refractive indices n₁, n₂, n₃ and n₄ is shown in the figure. The velocity of light will be maximum in the medium whose refractive index is

A thin symmetric double convex lens of power P is cut into three parts A, B and C as shown. The power of

A student has been given a project to prepare an astronomical telescope. Which two types of lenses does she have to buy?

An object is placed at a distance of x₁ from the focus on the principal axis of the concave mirror. The image is formed at a distance x₂ from the focus. Then, the focal length of the mirror is

The image of a candle formed by a convex lens is found to be real and inverted. What change would be found in the nature of this image if the lower half of the lens is covered with black paper?