If an electron moves from rest from a point at which potential is 50 text V to another point at which potential is 70 text V, then its kinetic energy in the final state will be

Question

If an electron moves from rest from a point at which potential is 50 text V to another point at which potential is 70 text V, then its kinetic energy in the final state will be (A)  3.2× 10-20J  (B)  3.2× 10-18J  (C)  3.2× 10-19J  (D) zero

Tardigrade Admin · Accepted Answer

The kinetic energy required by the particle is KE = q Δ v Given, q=e=1.6 × 10-19 C Δ V=V2-V1=70-50=20 V ∴ K E=1.6 × 10-19 × 20 =3.2 × 10-18 J

Q. If an electron moves from rest from a point at which potential is $50 V$ to another point at which potential is $70 V,$ then its kinetic energy in the final state will be

$3.2 \times 1 0^{- 20} J$

$3.2 \times 1 0^{- 18} J$

$3.2 \times 1 0^{- 19} J$

zero

The kinetic energy required by the particle is
$K E = q Δ v$
Given, $q = e = 1.6 \times 1 0^{- 19} C$
$Δ V = V_{2} - V_{1} = 70 - 50 = 20 V$
$∴ K E = 1.6 \times 1 0^{- 19} \times 20$
$= 3.2 \times 1 0^{- 18} J$

Q. If an electron moves from rest from a point at which potential is 50V to another point at which potential is 70V, then its kinetic energy in the final state will be

3.2×10−20J

3.2×10−18J

3.2×10−19J