Question

The photograph of a house occupies an area of 1.75 cm² on a 35 mm slide. The slide is projected on to a screen, and the area of the house on the screen is 1.55 m². What is the linear magnification of the projector-screen arrangement?

Answer 1

Area of the house = 1.75 cm²

Let’s assume that the house is square in shape.

Length of a side of the house = √175 cm

Area of the house on the screen 1.55 m²

Length of a side of the house on the screen

= √1.55 m = √1.55 × 100 cm

Linear magnification = length on the screen/length on the side

= ((√1.55 x 100 cm)/√1.75)

= 94.1