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Standard XII

Physics

Work Function

The surface o...

Question

The surface of a metal is illuminated with the light of $400 n m$ . The kinetic energy of the ejected photoelectrons was found to be 1.68 $e V$ . The work function of the metal is :
( $h c = 1240$ $e V . n m$ )

3.09

e V

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1.41

e V

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1.51

e V

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1.68

e V

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Solution

The correct option is A $1.41$ $e V$
From the photoelectric equation, $\frac{h c}{λ} = ϕ + ($ KE $)_{max}$

$\frac{1240}{400} = ϕ + 1.68$

$\Rightarrow ϕ = 1.41 e V$

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The surface of a metal is illuminated with the light of 400nm. The kinetic energy of the ejected photoelectrons was found to be 1.68 eV. The work function of the metal is : (hc=1240 eV.nm)

The correct option is A 1.41 eVFrom the photoelectric equation, hcλ=ϕ+( KE )max1240400=ϕ+1.68⇒ϕ=1.41eV

The surface of a metal is illuminated with the light of $400 n m$ . The kinetic energy of the ejected photoelectrons was found to be 1.68 $e V$ . The work function of the metal is :
( $h c = 1240$ $e V . n m$ )

The correct option is A $1.41$ $e V$
From the photoelectric equation, $\frac{h c}{λ} = ϕ + ($ KE $)_{max}$

$\frac{1240}{400} = ϕ + 1.68$

$\Rightarrow ϕ = 1.41 e V$