The GATE Grind

GATE 2014 EC (EC3) – Question 63

Engineering Mathematics · Vector Analysis · 2 marks · Numerical answer

$\mathbf A=(\cos x)(\sin y)\hat a_x+(\sin x)(\cos y)\hat a_y$. Find $|\nabla\times\mathbf A|$.

Practise this question in The GATE Grind →

Show answer and explanation

Correct answer: -0.01 to 0.01

Explanation

The only possible curl component is along z:∂Ay/∂x−∂Ax/∂y. Both derivatives equal cosxcosy because Ay=sinxcosy and Ax=cosxsiny. Their difference is zero, and there are no z-dependent components. Thus the curl vector and its magnitude are **0**.