The threshold frequency of the metal of the cathode in a photoelectric cell is 1× 1015Hz. When a certain beam of light is incident on the cathode, it is found that a slopping potential 4.144 V is required to reduce the current to zero. The frequency of the incident radiation is

Question

The threshold frequency of the metal of the cathode in a photoelectric cell is 1× 1015Hz. When a certain beam of light is incident on the cathode, it is found that a slopping potential 4.144 V is required to reduce the current to zero. The frequency of the incident radiation is (A)  2.5× 1015Hz  (B)  2× 1015Hz  (C)  4.144× 1015Hz  (D)  3× 1016Hz

Tardigrade Admin · Accepted Answer

V0=(h/e)(v-v0) or (v-v0)=(V0× e/h) =(4.144× 1.6× 10-19/6.63× 10-34) v-1× 105=1015 Frequency =1015+1× 1015 =2× 1015Hz

Q. The threshold frequency of the metal of the cathode in a photoelectric cell is $1 \times 10^{15} Hz .$ When a certain beam of light is incident on the cathode, it is found that a slopping potential 4.144 V is required to reduce the current to zero. The frequency of the incident radiation is

$2.5 \times 10^{15} Hz$

$2 \times 10^{15} Hz$

$4.144 \times 10^{15} Hz$

$3 \times 10^{16} Hz$

$V_{0} = \frac{h}{e} (v - v_{0})$ or $(v - v_{0}) = \frac{V _{0} \times e}{h}$ $= \frac{4.144 \times 1.6 \times 10 ^{- 19}}{6.63 \times 10 ^{- 34}}$ $v - 1 \times 10^{5} = 10^{15}$ Frequency $= 10^{15} + 1 \times 10^{15}$ $= 2 \times 10^{15} Hz$

Q. The threshold frequency of the metal of the cathode in a photoelectric cell is 1×1015Hz. When a certain beam of light is incident on the cathode, it is found that a slopping potential 4.144 V is required to reduce the current to zero. The frequency of the incident radiation is

2.5×1015Hz

2×1015Hz

4.144×1015Hz

3×1016Hz