Question

Time taken by the light to reach the surface of the earth from the sun is _____ .

• A. 8 minutes
• B. 3 minutes
• C. 8 s
• D. 80 s

Answer 1

The correct option is A 8 minutes

$\begin{array}{c}\text{The distance from Earth to sun is approx.}144\text{million}km=1.44\times {10}^{11}m\\ \text{and we know that speed of light is}3\times {10}^{8}m/s\text{.}\\ \therefore \text{time taken by sunlight}=\frac{\text{distance}}{\text{spced}}\\ \text{to reach earth}\\ \begin{array}{cc}& =\frac{1.44\times {10}^{11}}{3\times {10}^8}\\ & \approx 8\text{minutes.}\end{array}\\ \therefore \text{time taken by sunlight to reach earth is}8\text{minutes.}\end{array}$

Hence Option A is correct