Question

1. The illuminance on a surface is 6 lux and the surface is 4 meters from the light source. What is the intensity of the source?

Answer 1

1. Is A 96 candelas

2. I think it's D, I'm not sure

3. Is C 5 meters

Answer 2

Answer

1) A. 96 Candelas

2) A. Both of these types of lenses have the ability to produce upright images.

3) C. 5 meters

Explanation

Q1

The formula for calculation the luminous intensity is;

Luminous intensity = illuminance × square radius

Lv = Ev × r²

= 6 × 4²

= 6 × 16

= 96 Candelabra

Q2

For converging lenses, an upright image is formed when the object is between the lens and the principal focus while a diverging lens always forms and upright image.

A. Both of these types of lenses have the ability to produce upright images.

Q3

Luminous intensity = illuminance × square radius

square radius = Luminous intensity/ illuminance

r² = 100/4

= 25

r = √25

= 5 m