Question

The photoelectric threshold wavelength fro silver is $\lambda \left( \lambda < \lambda _ { 0 } \right)$will be:

• A.
• B.
• C. $\frac { \mathrm { h } } { \mathrm { c } } \left( \frac { \lambda _ { 0 } - \lambda } { \lambda \lambda _ { 0 } } \right)$
• D.

Answer 1

Answer: (D)

Answer 2

: According to Einstein’s photoelectric equation

$K = \frac { h c } { \lambda } - \frac { h c } { \lambda _ { 0 } } = h c \left( \frac { 1 } { \lambda } - \frac { 1 } { \lambda _ { 0 } } \right) = h c \left( \frac { \lambda _ { 0 } - \lambda } { \lambda \lambda _ { 0 } } \right)$