The maximum wavelength of a beam of light that can be used to produce photoelectric effect on a metal is 250 nm. The energy of the electrons (in joule) emitted from the surface of the metal when a beam of light of wavelength 200 nm is used

Question

The maximum wavelength of a beam of light that can be used to produce photoelectric effect on a metal is 250 nm. The energy of the electrons (in joule) emitted from the surface of the metal when a beam of light of wavelength 200 nm is used (A) 89.61 × 10-22 (B) 69.81 × 10-22 (C) 18.96 × 10-20 (D) 19.86 × 10-20

Tardigrade Admin · Accepted Answer

Here λ0=250 nm =250 × 10-9 m λ=200 nm =200 × 10-9 m According to Einstein's photoelectric equation, K=h v-h v0,=(h c/λ)-(h c/λ0)=h c[(1/λ)-(1/λ0)] =6.63 × 10-34 × 3 × 108 ×[(1/200)-(1/250)] × (1/10-9) ∴ K=19.89 × 10-20 J

Q. The maximum wavelength of a beam of light that can be used to produce photoelectric effect on a metal is 250 nm. The energy of the electrons (in joule) emitted from the surface of the metal when a beam of light of wavelength 200 nm is used

$89.61 \times 1 0^{- 22}$

$69.81 \times 1 0^{- 22}$

$18.96 \times 1 0^{- 20}$

$19.86 \times 1 0^{- 20}$

Q. The maximum wavelength of a beam of light that can be used to produce photoelectric effect on a metal is 250 nm. The energy of the electrons (in joule) emitted from the surface of the metal when a beam of light of wavelength 200 nm is used

89.61×10−22

69.81×10−22

18.96×10−20

19.86×10−20

Here λ0​=250nm=250×10−9m λ=200nm=200×10−9m According to Einstein's photoelectric equation, K=hv−hv0​,=λhc​−λ0​hc​=hc[λ1​−λ0​1​] =6.63×10−34×3×108×[2001​−2501​]×10−91​ ∴K=19.89×10−20J

$89.61 \times 1 0^{- 22}$

$69.81 \times 1 0^{- 22}$

$18.96 \times 1 0^{- 20}$

$19.86 \times 1 0^{- 20}$