You are using a magnifier that gave you a lateral magnification of 1/2. If the object distance is 0.5 cm, calculate the focal length of the magnifier.

Respuesta :

Answer:

The focal length is -0.5.

Explanation:

Given that,

Magnification [tex]m=\dfrac{1}{2}[/tex]

Object distance u = 0.5 cm

We need to calculate the image distance

Using formula of magnification

[tex]m=-\dfrac{v}{u}[/tex]

Put the value into the formula

[tex]\dfrac{1}{2}=-\dfrac{v}{0.5}[/tex]

[tex]v=-\dfrac{1}{2}\times0.5[/tex]

[tex]v=-0.25\ cm[/tex]

We need to calculate the focal length

Using formula for focal length

[tex]\dfrac{1}{f}=\dfrac{1}{u}+\dfrac{1}{v}[/tex]

[tex]\dfrac{1}{f}=\dfrac{v+u}{vu}[/tex]

[tex]f=\dfrac{uv}{v+u}[/tex]

[tex]f=\dfrac{0.5\times(-0.25)}{-0.25+0.5}[/tex]

[tex]f=-0.5\ cm[/tex]

Hence, The focal length is -0.5.

Answer:

[tex]- 0.5[/tex] cm

Explanation:

[tex]M[/tex] = Lateral Magnification = 0.5

[tex]d_{o}[/tex] = Distance of the object = 0.5 cm

[tex]d_{i}[/tex] = Distance of the image = ?

Lateral magnification is given as

[tex]M = \frac{- d_{i}}{d_{o}}[/tex]

[tex]0.5 = \frac{- d_{i}}{0.5}[/tex]

[tex]d_{i} = - 0.25[/tex] cm

[tex]f[/tex] = focal length of the magnifier

Using the equation

[tex]\frac{1}{d_{o}} + \frac{1}{d_{i}} = \frac{1}{f}[/tex]

[tex]\frac{1}{0.5} + \frac{- 1}{0.25} = \frac{1}{f}[/tex]

[tex]f = - 0.5[/tex] cm