Question

Assertion: If an electron is not deflected while passing through a certain region of space, then only possibility is that there is no magnetic field in this region

Reason: Magnetic force is directly proportional to magnetic field applied

• A. Assertion is true but reason is false
• B. Assertion is false but reason is true
• C. Both assertion and reason are true and reason is correct explanation of the assertion.
• D. Both assertion and reason are true and reason is not a correct explanation of the assertion.

Answer 1

Answer: (B)

$\overline{F}=q(\overline{v}\times \overline{B})$
$F=qvB\sin \theta$
if $\theta =0$, $F=0$
then particle will also not deflect.
And $F\alpha B$