Question

Which the following series fall in the visible range of electromagnetic spectrum?

• A. 14.4 Å
• B. 14.4 $\frac { Z } { V }$ m
• C. 14.4 $\frac { Z } { V }$ cm
• D. All of these

Answer 1

Answer: (A)

14.4 Å

Answer 2

K.E. = P.E. = qV

2eV = $\frac { K ( Z e ) ( 2 e ) } { d }$ = qV

∴ d = $\frac { 9 \times 10 ^ { 9 } \times \mathrm { Z } \times \mathrm { e } \times 2 \mathrm { e } } { 2 \mathrm { eV } }$

∴ d =

d = 14.4 × 10^–10 $\left( \frac { \mathrm { Z } } { \mathrm { V } } \right)$ m