Question

2 a)If the radius of curvature of the given mimor is 10 cm, Calculate its focal length?​

Answer 1

Answer:

If the radius of curvature of the given mirror is 10 cm, its focal length will be $0.05\ m$

Explanation:

• The distance from the pole to the center of curvature of the mirror is called the radius of curvature.

• Focal length is the distance between the pole of the mirror and the focus of the object.

• The radius of curvature will be twice the focal length

• Let R be the radius of curvature and f be the focal length then,

       $R = 2f$    ...(1)

In the question, it is given that,

$R = 10\ cm = 10\times 10^{-2} m$

Using equation (1),

$f = \frac{R}{2}$

Substitute  the value of R into the above equation,

 $f = \frac{10\times 10^{-2} }{2} = 0.05\ m$  

Answer 2

Given: Radius of the curvature(R)=10 cm

To find The focal length

Solution:

• In Physics, there is a separate branch that discusses the phenomenon of light, and this branch is known as optics. In optics, we discuss the reflection of light.

• The radius of a circle in which a mirror that is spherical is a part is known as the radius of curvature.

• The distance of a spherical mirror from a focal point is termed the focal length.
• We know that focal length= radius of curvature/2

                                      f=R/2

From above, we have R=10cm

∴ f=R/2

⇒f=10/2  [substituting the value of R]

⇒f=5cm

Hence the focal length is 5cm.