Question

(a) What do you mean by ‘order of magnitude’? (b) Find the order of magnitude of light year.

Answer 1

(a) Order of magnitude is defined as the power of 10 used to express the magnitude of a physical quantity under consideration, e.g.,

(i) Order of magnitude of time intervals of 1.2 × 10^-6 s is -6.

(ii) Order of magnitude of distance of 4.5 ×10⁶ is +6.

(b) 1 light year = 9.46 × 10¹⁵ m = 10¹⁶ m

∴ Order of magnitude of light year is 16.