Question

i will select brainliest answer !!!!!

Answer 1

Solution :

⏭ Given:

• mass of particle = m
• charge on particle = q
• initial velocity of particle = 0
• magnitude of electric field = E
• time interval = t

⏭ To Find:

✏ Kinetic energy of the charged particle after t second...

⏭ Concept:

✏ Here net force acts on charged particle is electrical force.

⏭ Formula:

✏ As per first equation of kinematics relation between initial velocity, final velocity, time and acceleration is given by...

$\bigstar \: \boxed{ \sf{ \large{ \pink{v = u + at}}}} \: \bigstar$

⏭ Calculation:

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• Final velocity of particle

$\implies \sf \: net \: force = qE \\ \\ \implies \sf \: ma = qE \\ \\ \implies \sf \: \red{a = \dfrac{qE}{m}} \\ \\ \circ \sf \: \: v = 0 + at \\ \\ \circ \: \: \boxed{ \sf{ \green{v = \dfrac{qEt}{m} }}}$

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• Kinetic energy of particle

$\mapsto \sf \: k = \dfrac{1}{2} m {v}^{2} \\ \\ \mapsto \sf \: k = \frac{1}{2} \times m \times \dfrac{ {q}^{2} {E}^{2} {t}^{2} }{ {m}^{2} } \\ \\ \mapsto \: \boxed{ \sf{ \orange{k = \frac{ {q}^{2} {E}^{2} {t}^{2} }{2m} }}}$

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✒ Option-B) is correct