# National Standard Examination in Astronomy (NSEA) Solved Paper 2016 Part-5

Q: 13. A train is running on a circular track of radius R with a constant speed, The driver is blowing siren of a constant frequency () throughout the circular motion of period T. There is a listener on the diameter of the track at a distance R/2 from centre of the circle. At t = 0, the train siren is farthest from the listener. In the following graphs the frequency, as recorded by the listener, is plotted against time. Which of them is closes to the correct pattern?

(A) Driver is Blowing Siren of a Constant Frequency Choice A The driver is blowing siren of a constant frequency (n0)

(B) Driver is Blowing Siren of a Constant Frequency Choice B Q-13 B The driver is blowing siren of a constant frequency (n0) throughout the circular motion of period T.

(C) Driver is Blowing Siren of a Constant Frequency Choice C Q-13 C The driver is blowing siren of a constant frequency (n0) throughout the circular motion of period T.

(D) Driver is Blowing Siren of a Constant Frequency Choice D Q-13 D The driver is blowing siren of a constant frequency (n0) throughout the circular motion of period T.

Q: 14. If {x} denotes the fractional part of a real number then

(A)

(B)

(C)

(D)