Threshold frequency of a metal is 5 × 1013 s-1 upon which 1 × 1014 s-1 frequency light is focused. Then the maximum kinetic energy of emitted electron is

Question

Threshold frequency of a metal is 5 × 1013 s-1 upon which 1 × 1014 s-1 frequency light is focused. Then the maximum kinetic energy of emitted electron is (A) 3.3 × 10-21 (B) 3.3 × 10-20 (C) 6.6 × 10-21 (D) 6.6 × 10-20

Tardigrade Admin · Accepted Answer

Following the conservation of energy principle,
Kinetic energy

(\frac{1}{2} m_{e} υ^{2}) = h (υ - υ_{0})

= (6.626 × 10^-34 J s) (1 × 10¹⁴ s^-1 - 5 × 10¹³ s^-1)

= (6.626 × 10^-34 J s) (5 × 10¹³ s^-1)

= 3.313 × 10^-20 J

Q. Threshold frequency of a metal is 5 × 10¹³ s^-1 upon which 1 × 10¹⁴ s^-1 frequency light is focused. Then the maximum kinetic energy of emitted electron is

3.3 × 10^-21

3.3 × 10^-20

6.6 × 10^-21

6.6 × 10^-20

Following the conservation of energy principle,
Kinetic energy $(\frac{1}{2} m_{e} υ^{2}) = h (υ - υ_{0})$
= (6.626 × 10^-34 J s) (1 × 10¹⁴ s^-1 - 5 × 10¹³ s^-1)
= (6.626 × 10^-34 J s) (5 × 10¹³ s^-1)
= 3.313 × 10^-20 J

Q. Threshold frequency of a metal is 5 × 1013 s-1 upon which 1 × 1014 s-1 frequency light is focused. Then the maximum kinetic energy of emitted electron is

3.3 × 10-21

3.3 × 10-20

6.6 × 10-21

6.6 × 10-20