Answer:
3) C
4 D
5) C
Explanation:
3) given that
Initial distance of the screen = 100cm
Initial area = 150 cm^2
Final distance = 200 cm
The intensity of light is inversely proportional to the square of the distance. That is
Intensity of light I = 1/d2
And also I = P/A
1/d^2 = P/A
P = A/d^2
P1 = P2
150/100 = A/200
1.5 = A/200
A = 1.5 × 200
A = 300 cm^2
4.) Light is projected onto a screen 75.0 cm from a light source. The light intensity = 4436 lux
If the screen is moved from 75.0 cm to 150. cm, the light sensor reading will be
Using inverse square law
I = 1/d^2
I×d^2 = constant. Therefore,
4436 × 75^2 = I × 150^2
I = 24952500/22500
I = 1109 lux
5.) We can express the relationship between luminosity, brightness, and distance with a simple formula.
As we tilt the serene the area of light decreases and makes the light more concentrated.
