The length of the chord of the circle x²+y²+4x -7y+12 =0 along the y- axis is

a. 1

b. 2

c. 1/2

d. n.o.t.

First, we find the points where the given circle intersects the y-axis.

We know that the abscissae of points lying on the y-axis is 0.

So we put x = 0 in the given equation of the circle to find the ordinate/s of the point where the circle intersects y-axis.

So, we get, (0)² + y² + 4(0) -7y + 12 = 0

or y² -7y + 12 = 0

or (y - 3)(y - 4) = 0

which implies that y = 3 or y = 4.

Hence the circle intersects the y-axis at (0,3) and (0,4)

Distance between the points (0,3) and (0,4) is 1 unit.

Hence the length of the chord along y-axis is 1 unit.

or