Physics
Grade-10
Easy
Question
The speed of light in a vacuum is ______ m/s.
- 3 x 109
- 2 x 109
- 3 x 108
- 2 x 108
Hint:
The speed of light in vacuum is a universal physical constant that is commonly denoted c.
The correct answer is: 3 x 108
The speed of light in air or vacuum is 3 x 108 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
Physics
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 _____.
PhysicsGrade-10
the center of curvature and focus lies behind the convex mirror, hence the signs are taken as positive.
Physics
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 _____.
PhysicsGrade-10
Physics
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 _____.
PhysicsGrade-10
Physics
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.
PhysicsGrade-10
Physics
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.
PhysicsGrade-10
Physics
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 _____.
PhysicsGrade-10
Physics
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?
PhysicsGrade-10
Physics
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 ____.
PhysicsGrade-10
Physics
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.)
PhysicsGrade-10
all the given cases show negative signs for a concave mirror.
Physics
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 _____.
PhysicsGrade-10
Physics
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.)
PhysicsGrade-10
both the height of an object and the height of a virtual and upright image are positive.
Physics
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 _____.
PhysicsGrade-10
the real image is always formed as inverted, therefore, for real image height is taken as negative.
Physics
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?
PhysicsGrade-10
Physics
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.
PhysicsGrade-10
object is always placed to the left of mirror.
Physics
The magnification of an image is found to be -2.5. Which of the following is true about it?
a. It is real and inverted
b. It is diminished
c. It is magnified
d. It is formed in front of the concave mirror
e. It is formed behind the mirror
f. It is virtual and upright
The magnification of an image is found to be -2.5. Which of the following is true about it?
a. It is real and inverted
b. It is diminished
c. It is magnified
d. It is formed in front of the concave mirror
e. It is formed behind the mirror
f. It is virtual and upright
PhysicsGrade-10
