Light – Reflection and Refraction Class 10 MCQ Quiz – Test Your Understanding!

No matter how far you stand from this spherical mirror, your image always appears erect. The mirror may be:

If the power of a lens is - 4.0 D,  then it means that the lens is a _____.

Sumati wanted to see the stars of the night sky. She knows that she needs a telescope to see those distant stars. She finds out that the telescopes, which are made of lenses, are called telescopes and the ones which are made of mirrors are called reflecting telescopes.

So she decided to make a refracting telescope. She bought two lenses L₁ and L₂ out of which L₁ was bigger and L₂ was smaller. The larger lens gathers and bends the light, while the smaller lens magnifies the image. Big, thick lenses are more powerful. So to see far away, she needed a big powerful lens. Unfortunately, she realized that a big lens is very heavy.

Heavy lenses are hard to make and difficult to hold in the right place. Also since the light is passing through the lens, the surface of the lens has to be extremely smooth. Any flaws in the lens will change the image. It would be like looking through a dirty window.

If the powers of the lenses L₁ and L₂ are in the ratio of 4:1, what would be the ratio of the focal length of L₁ and L₂?

While looking at the below diagram, Nalini concluded the following:

1. The image of the object will be a virtual one.
2. The reflected ray will travel along the same path as the incident ray but in the opposite direction.
3. The image of the object will be inverted.
4. This is a concave mirror and hence the focal length will be negative.

Which one of the above statements is correct?

A. Noor, a young student, was trying to demonstrate some properties of light in her science project work. She kept ‘X’ inside the box (as shown in the figure) and with the help of a laser pointer made light rays pass through the holes on one side of the box. She had a small butter paper screen to see the spots of light being cast as they emerged.

What could be the ‘X’ that she placed inside the box to make the rays behave as shown?

A small electric lamp is placed at the focus of a convex lens. When the lamp is switched on, the lens will produce:

In the diagram shown below, a beam of light is traveling from inside a glass slab to air. Which of the marked paths will the ray of light take as it emerges from the glass slab?

Rays from the sun converge at a point 15 cm in front of a concave mirror. Where should an object be placed so that the size of its image is equal to the size of the object?

Rajan takes the following two photographs of the text in a book, first while keeping a circular piece of glass on the book and then while holding it at some distance above the book.

Which of the following statements is true about the piece of glass?

If the real image of a candle flame formed by a lens is three times the size of the flame and the distance between the lens and image is 80 cm, at what distance should the candle be placed from the lens?

The refractive index of flint glass is 1.65 and that for alcohol is 1.36 with respect to air. What is the refractive index of the flint glass with respect to alcohol?

The angle of incidence from air to glass at point O on the hemispherical glass slab is _____.

Consider these indices of refraction:

• Glass: 1.52
• Air: 1.0003
• Water: 1.333

Based on the refractive indices of three materials, arrange the speed of light through them in decreasing order.

Sumati wanted to see the stars of the night sky. She knows that she needs a telescope to see those distant stars. She finds out that the telescopes, which are made of lenses, are called telescopes and the ones which are made of mirrors are called reflecting telescopes.

So she decided to make a refracting telescope. She bought two lenses L₁ and L₂ out of which L₁ was bigger and L₂ was smaller. The larger lens gathers and bends the light, while the smaller lens magnifies the image. Big, thick lenses are more powerful. So to see far away, she needed a big powerful lens. Unfortunately, she realized that a big lens is very heavy.

Heavy lenses are hard to make and difficult to hold in the right place. Also since the light is passing through the lens, the surface of the lens has to be extremely smooth. Any flaws in the lens will change the image. It would be like looking through a dirty window.

Based on the diagram shown, what kind of lenses would Sumati need to make the telescope?

Assertion (A): Refractive index has no units.

Reason (R):  The refractive index is the ratio of two similar quantities.