# SIR PLEASE TELL ME THE CONCEPT OF ABOVE QUESTION IN THE IMAGE

Susmita
425 Points
3 years ago
When any charged particle q1 is placed in potential V,its potential energy is q1V.Just like  when we apply a voltage difference across a conducting wire in a circuit,the electrons starts to flow,ie,the electrons acquire some velocity or kinetic energy.
Who supplies this kinetic energy?The potential difference,or the potential energy.
So q1V=(1/2)mv2
or,v=root(2q1V/m)
Now it enters a magnetic field B perpendicularly.So force experienced is
$F=q_{1}|\vec{v}*\vec{B}|=q_{1}vB=q_{1}B\sqrt{\frac{2q_{1}V}{m}}$
Later it is accelerated through a potential 5V.
So its velocity will increase to
v=root(2q1.5V/m)
Now the force
$F'=q_{1}B\sqrt{\frac{2q_{1}*5V}{m}}=\sqrt{5}F$