An electron beam has a kinetic energy equal to 100 eV. Find its wavelength associated with a beam, if mass of electron =9.1 × 10-31 kg and 1 eV =1.6 × 10-19 J / eV (Planck's constant =6.6 × 10-34 J - s )

Question

An electron beam has a kinetic energy equal to 100 eV. Find its wavelength associated with a beam, if mass of electron =9.1 × 10-31 kg and 1 eV =1.6 × 10-19 J / eV (Planck's constant =6.6 × 10-34 J - s ) (A)  6.3 mathringA (B)  3.8 mathringA (C)  24.6 mathringA (D)  0.12 mathringA

Tardigrade Admin · Accepted Answer

de-Broglie's wavelength associated with a charged particle, λ=(h/√2 m K E) =(6.6 × 10-34/√2 × 9.1 × 10-31 × 10 × 1.6 × 10-19)=3.8 mathringA

Q. An electron beam has a kinetic energy equal to $100 e V$ . Find its wavelength associated with a beam, if mass of electron $= 9.1 \times 1 0^{- 31} k g$ and $1 e V$ $= 1.6 \times 1 0^{- 19} J / e V$ (Planck's constant $= 6.6 \times 1 0^{- 34} J - s$ )

$6.3 \overset{˚}{A}$

$3.8 \overset{˚}{A}$

$24.6 \overset{˚}{A}$

$0.12 \overset{˚}{A}$

de-Broglie's wavelength associated with a charged particle, $λ = \frac{h}{2 m K E}$
$= \frac{6.6 \times 1 0 ^{- 34}}{2 \times 9.1 \times 1 0 ^{- 31} \times 10 \times 1.6 \times 1 0 ^{- 19}} = 3.8 \overset{˚}{A}$

Q. An electron beam has a kinetic energy equal to 100eV. Find its wavelength associated with a beam, if mass of electron =9.1×10−31kg and 1eV =1.6×10−19J/eV (Planck's constant =6.6×10−34J−s )

6.3A˚

3.8A˚

24.6A˚

0.12A˚