If the electric potential in a region varies as V=4y² , then electric field at point (2,3) in that region is . . .

Question : If the electric potential in a region varies as V=4y² , then electric field at point (2,3) in that region is 

a) 24V/m along +X axis 
b) 48V/m along - X axis
c) 24V/m along +Y axis
d) 24V/m along -Y axis

Doubt by Tushar

Solution : Coming Soon 
We know, E=-dV/dr
Ex=-d(4y²)/dx = 0
Ey=-d(4y²)/dt=-8y
Ey(y=3) = -8×3 = -24

E = [Exi+Eyj] V/m
E = 0i+(-24)j
E=(-24 j) V/m

Hence, Correct Answer is option d) 24V/m along -Y axis