Question

The magnitude of light year is

• A. $9.46\times {10}^{12}km$
• B. $4.96\times {10}^{12}km$
• C. $9.64\times {10}^{12}km$
• D. $6.94\times {10}^{12}km$

Answer 1

The correct option is A

$9.46\times {10}^{12}km$

1. A light-year is defined as the measurement of length or the distance light travels in a vacuum in a year. One light-year is close to 6 trillion miles.

2. Example of a light-year

a. Reflected sunlight travelling from the moon’s surface takes 4.04 × 10^-8 light-years to reach the earth.

b. It takes 1.58 × 10^-5 light-years for light from the Sun to reach the earth.

3. The value of one light-year can be numerically expressed in kilometres as:

One light-year, ly = 9.4607 × 10¹² km

4. Hence, the correct answer is option A.