Ultraviolet radiation of 6.2 eV falls on an aluminium surface (work function 4.2 eV). The kinetic energy in joule of the fastest electron emitted is approximately

Question

Ultraviolet radiation of 6.2 eV falls on an aluminium surface (work function 4.2 eV). The kinetic energy in joule of the fastest electron emitted is approximately (A)  3.2× 10-21  (B)  3.2× 10-19  (C)  3.2× 10-17  (D)  3.2× 10-15

Tardigrade Admin · Accepted Answer

K max (eV)=E(eV)-W0(eV) =6.2-4.2=2eV ∴ K max (J)=2× 1.6× 1019J =3.2× 10-19J

Q. Ultraviolet radiation of 6.2 eV falls on an aluminium surface (work function 4.2 eV). The kinetic energy in joule of the fastest electron emitted is approximately

$3.2 \times 10^{- 21}$

$3.2 \times 10^{- 19}$

$3.2 \times 10^{- 17}$

$3.2 \times 10^{- 15}$

$K_{m a x} (e V) = E (e V) - W_{0} (e V)$
$= 6.2 - 4.2 = 2 e V$
$∴$ $K_{m a x} (J) = 2 \times 1.6 \times 10^{19} J$
$= 3.2 \times 10^{- 19} J$

Q. Ultraviolet radiation of 6.2 eV falls on an aluminium surface (work function 4.2 eV). The kinetic energy in joule of the fastest electron emitted is approximately

3.2×10−21

3.2×10−19

3.2×10−17

3.2×10−15

Kmax​(eV)=E(eV)−W0​(eV) =6.2−4.2=2eV ∴ Kmax​(J)=2×1.6×1019J =3.2×10−19J

$3.2 \times 10^{- 21}$

$3.2 \times 10^{- 19}$

$3.2 \times 10^{- 17}$

$3.2 \times 10^{- 15}$

$K_{m a x} (e V) = E (e V) - W_{0} (e V)$
$= 6.2 - 4.2 = 2 e V$
$∴$ $K_{m a x} (J) = 2 \times 1.6 \times 10^{19} J$
$= 3.2 \times 10^{- 19} J$