Monochromatic radiation emitted when electron on hydrogen atom jumps from first excited to the ground state irradiates a photosensitive material. The stopping potential is measured to be 3.57 V. The threshold frequency of the material is

Question

Monochromatic radiation emitted when electron on hydrogen atom jumps from first excited to the ground state irradiates a photosensitive material. The stopping potential is measured to be 3.57 V. The threshold frequency of the material is (A) 4 × 1015 Hz (B) 5 × 1015 Hz (C) 1.6 × 1015 Hz (D) 2.5 × 1015 Hz

Tardigrade Admin · Accepted Answer

Energy released from emmition of electron is E =(-3.4)-(-13.6)=10.2 eV. From photo-electric equation, work function φ= E - eV 0= h v 0 On Solving this v0=1.6 × 1015 Hz

Q. Monochromatic radiation emitted when electron on hydrogen atom jumps from first excited to the ground state irradiates a photosensitive material. The stopping potential is measured to be $3.57 V .$ The threshold frequency of the material is

$4 \times 1 0^{15} Hz$

$5 \times 1 0^{15} Hz$

$1.6 \times 1 0^{15} Hz$

$2.5 \times 1 0^{15} Hz$

Energy released from emmition of electron is
$E = (- 3.4) - (- 13.6) = 10.2 e V$ .
From photo-electric equation, work function $ϕ = E - e V_{0} = h v_{0}$
On Solving this $v_{0} = 1.6 \times 1 0^{15} Hz$

Q. Monochromatic radiation emitted when electron on hydrogen atom jumps from first excited to the ground state irradiates a photosensitive material. The stopping potential is measured to be 3.57V. The threshold frequency of the material is

4×1015Hz

5×1015Hz

1.6×1015Hz

2.5×1015Hz