Question

Match List - I (Event) with List - II (Order of the time interval for happening of the event) and select the correct option from the options given below the lists.

	List - I		List - II
(a)	Rotation period of earth	(i)	${10}^{5}s$
(b)	Revolution period of earth	(ii)	${10}^{7}s$
(c)	Period of a light wave	(iii)	${10}^{-15}s$
(d)	Period of a sound wave	(iv)	${10}^{-3}s$

• A. (a)-(i), (b)-(ii), (c)-(iii), (d)-(iv)
• B. (a)-(ii), (b)-(i), (c)-(iv), (d)-(iii)
• C. (a)-(i), (b)-(ii), (c)-(iv), (d)-(iii)
• D. (a)-(ii), (b)-(i), (c)-(iii), (d)-(iv)

Answer 1

The correct option is A (a)-(i), (b)-(ii), (c)-(iii), (d)-(iv)

The rotation period of the Earth is 24 hrs

This is equivalent to 24*3600 = 8.64 $\times {10}^4$ s = ${10}^5$ s

Similarly, the revolution period of earth is 365 days = ${10}^7$ s

The velocity of a light wave is ${10}^8$ m/s and its wavelength is ${10}^{-7}$ m

Thus, using, $v=\nu \lambda$, the order of time is ${10}^{-15}$

And thereby, the time period of sound wave is ${10}^{-3}$ s