106Ques) If Ck is a circle of eqn x2 + y2 = k2 ; k belongs to N, a point moves k units on Ck in anticlockwise direction then goes to C k+1 and so on. If point starts frm (1,0) and Ist time crosses the +ve x-axis on circle Cn , then the value of n equals to
(a) 7 (b) 6 (c) 5 (d) 13
starts from (1,0) goes 1 unit on C1 anticlockwise i.e. covers 1 rad.
Each circle it covers 1 rad.
so, C2 -- > 2rad (end point)
C3 --> 3rad
C4 --> 4rad
.
.
.
C6--> 6rad
C7 --> 7rad
Now 2pi rad = 6.28 rad.
So it will be on the 7th circle when crossing the x-axis.
