A charged particle moves along positive y-axis with constant velocity in uniform electric and magnetic fields. Ilf magnetic fiedl is actig along positive x-axis, then, electric field should act along positive z-axis.
Reason: To keep the charged particle undeviated the relation `E=Bxxv` must hold good.

Options

A. If both Assertion and Reason are true and the Reason is correct explanation of the Assertion.
B. If both Assertion and Reason are true but Reason is not the correct explanation of Assertion
C. If Assertion is true, but the Reason is false.
D. If Assertion is false but the Reason is true.

Answer

A

Explanation

`:' F_e+F_m=0`
`:.qE+q(vxxB)=0`
`:. E=-(vxxB)=(Bxxv)`