1) An object is 1.0 cm tall and its inverted image is 3.0 cm tall. What is the exact magnification?

2) A ** ____**can be considered as an ultrathin beam of light that travels in a straight line until it meets a reflecting or refracting surface.

### Answer

1) Use the following formula to find the magnification.

`m=-\frac{\text { image height }}{\text { object height }}`

`=-\frac{3 \mathrm{~cm}}{1 \mathrm{~cm}}`

`=-3 \mathrm{~cm}`

2) A Light ray can be considered as ultrathin beam of light that travels in a straight line until it meets a reflecting or refracting surface.