Question

# The refractive index of air is ____.

- 1
- 2
- 3
- 4

Hint:

### The **ratio of the speed of light** as it travels through two mediums is known as the **refractive index,** sometimes known as the **index of refraction**. It is a** dimensionless number that changes with temperature and light beam wavelength.**

## The correct answer is: 1

### The refractive index of air is 1.

- The refractive index is the ratio of the speed of light in two different mediums i.e- medium 1 and medium 2.
- The air has no density as compared to a medium like glass or water.
- The refractive index of air or the refractive index of the atmosphere is approximately 1.002 which implies that the speed of light in air is 1.002 times slower than that in a vacuum.

### Related Questions to study

### The speed of light in a vacuum is ______ m/s.

### The speed of light in a vacuum is ______ m/s.

### The radius of curvature of a convex mirror is taken to be _____.

the center of curvature and focus lies behind the convex mirror, hence the signs are taken as positive.

### The radius of curvature of a convex mirror is taken to be _____.

the center of curvature and focus lies behind the convex mirror, hence the signs are taken as positive.

### For an image formed behind a mirror towards the right, the sign for the image distance is _____.

### For an image formed behind a mirror towards the right, the sign for the image distance is _____.

### For an object standing in front of a spherical mirror, the object distance is _____.

### For an object standing in front of a spherical mirror, the object distance is _____.

### The height of a virtual and upright image is ____ as per the new cartesian sign convention.

### The height of a virtual and upright image is ____ as per the new cartesian sign convention.

### The height of a real and inverted image is _____ as per the new cartesian sign convention.

### The height of a real and inverted image is _____ as per the new cartesian sign convention.

### Before plugging in the values of various quantities in the expression to calculate the magnification it is important to _____.

### Before plugging in the values of various quantities in the expression to calculate the magnification it is important to _____.

### The magnification of the image of an object is found to be 1.25. Which of the following is true about it?

### The magnification of the image of an object is found to be 1.25. Which of the following is true about it?

### An object is placed at a distance of 20 cm from a convex mirror. Its image is formed at a distance of 10 cm from the mirror. The magnification is ____.

### An object is placed at a distance of 20 cm from a convex mirror. Its image is formed at a distance of 10 cm from the mirror. The magnification is ____.

### Which of the following should be taken as negative according to the new cartesian sign convention? (Note: the object is standing in front of a concave mirror.)

all the given cases show negative signs for a concave mirror.

### Which of the following should be taken as negative according to the new cartesian sign convention? (Note: the object is standing in front of a concave mirror.)

all the given cases show negative signs for a concave mirror.

### The height of a real and inverted image of an object of size 4 cm is 20 cm. The ratio of the image distance and the object distance is _____.

### The height of a real and inverted image of an object of size 4 cm is 20 cm. The ratio of the image distance and the object distance is _____.

### Which of the following should be taken as positive according to the new cartesian sign convention? (Note: the object is standing in front of the mirror along the +y direction.)

both the height of an object and the height of a virtual and upright image are positive.

### Which of the following should be taken as positive according to the new cartesian sign convention? (Note: the object is standing in front of the mirror along the +y direction.)

both the height of an object and the height of a virtual and upright image are positive.

### A real image is always _____.

the real image is always formed as inverted, therefore, for real image height is taken as negative.

### A real image is always _____.

the real image is always formed as inverted, therefore, for real image height is taken as negative.

### An object of size 12 cm is placed in front of a concave mirror, it forms a real and inverted image of size 18 cm. What is the magnification of the image?

### An object of size 12 cm is placed in front of a concave mirror, it forms a real and inverted image of size 18 cm. What is the magnification of the image?

### The position of an object is always taken to be towards the ____ of the mirror.

object is always placed to the left of mirror.

### The position of an object is always taken to be towards the ____ of the mirror.

object is always placed to the left of mirror.