An electron is accelerated from rest, between two points A and B at which the potentials are 20 V and 40 V respectively. The De Broglie wavelength associated with the electron at B will be –
(1)0.75 Å(2)7.5 Å(3)2.75 Å(4)2.75 m
Answers
Answered by
27
the formula we use to calculate de broglie wavelength is 12.27/√V where V is the POTENTIAL DIFFERENCE NOT POTENTIAL OF A POINT....here potential diff. is 40-20=20 V..
now using formula 12.27/√20=2.27A°
now using formula 12.27/√20=2.27A°
Anonymous:
its wrong formula u use is for wavelength in metre
for wavelength in A° formula is √150/v
for an electron
root over 150 is 12.27..
but for correct approximation we have to use root value
for avoiding errors
can u see once more what i've done..
u can see that 2.27 is not any option
2.27 and 2.75 are very different from each other
Answered by
26
hey there....
we know that de- Broglie wave length
= h / mv
= h /√2qv
so after solving this equation we get,
Wave length = √( 150/v)
so answer is nearly equal to 2.75 A°
option C * is correct.
_______________________----_____
Hope it will help u
we know that de- Broglie wave length
= h / mv
= h /√2qv
so after solving this equation we get,
Wave length = √( 150/v)
so answer is nearly equal to 2.75 A°
option C * is correct.
_______________________----_____
Hope it will help u
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thanks..
(^_^)
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