Question

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

- 3 x 10
^{9} - 2 x 10
^{9 } - 3 x 10
^{8 } - 2 x 10
^{8 }

^{9}^{9 }^{8 }^{8 }Hint:

### The speed of light in vacuum is a **universal physical constant **that is commonly denoted **c.**

## The correct answer is: 3 x 10^{8 }

### The speed of light in air or vacuum is 3 x 10^{8} m/s

- When the light passes through a medium, the air is considered as medium 1.
- The speed of light in the air is more compared to medium 2.
- This is the speed of things with no mass, as mass is an impediment to motion: light, gravity waves. Since all light lacks mass, it moves at c.

### Related Questions to study

### 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.