Book Online Demo
Check Your IQ
Try Test
Courses
Dropper NEET CourseDropper JEE CourseClass - 12 NEET CourseClass - 12 JEE CourseClass - 11 NEET CourseClass - 11 JEE CourseClass - 10 Foundation NEET CourseClass - 10 Foundation JEE CourseClass - 10 CBSE CourseClass - 9 Foundation NEET CourseClass - 9 Foundation JEE CourseClass -9 CBSE CourseClass - 8 CBSE CourseClass - 7 CBSE CourseClass - 6 CBSE Course
Q.
An expression for de Broglie wavelength of matter waves is:
see full answer
Start JEE / NEET / Foundation preparation at rupees 99/day !!
21% of IItians & 23% of AIIMS delhi doctors are from Sri Chaitanya institute !!
An Intiative by Sri Chaitanya
a
b
c
d
None of these
answer is A.
(Unlock A.I Detailed Solution for FREE)
Ready to Test Your Skills?
Check your Performance Today with our Free Mock Test used by Toppers!
Take Free Test
Detailed Solution
Concept- We'll start by comparing Einstein's equation connecting matter and energy with Planck's equation, with the assumption that the energies in both cases are equal.
Formulas Used:
and
De Broglie obtained his equation using well-known ideas by making the following substitutions:
Einstein's famous equation connecting matter and energy states that
where
denotes energy,
denotes mass and
denotes the speed of light
Using Planck's theory which states every quantum of a wave has a discrete amount of energy given by Planck's equation
where
denotes the energy,
denotes the planck's constant and
denotes the frequency
The value of the planck's constant is given by
Joule-sec
Because physical particles do not travel at the speed of light, de Broglie substituted v for the particle's velocity for the speed of light (c)
We can solve the equation (1) by replacing c with v.
De Broglie theorised that because particles and waves had the same properties, their energy would be equal.
The LHS of both equations (2) and (3) is clearly the same (i.e., energy E). As a result, the RHS of both equations may be equaled and will be equal.


We can write anything based on the relationship between the wavelength, velocity, and frequency of any wave.
By substituting
in equation (4), we get


As we know that the momentum
is the product of mass
and the velocity
i.e.,
We get by inserting p = mv in equation (5).
where
denotes de Broglie wavelength of matter waves,
is planck's constant (
Joule-sec) and
denotes the momentum of the matter wave.
The above equation is the necessary expression for the de Broglie wavelength of matter waves.
Hence, the correct answer is option 1.
Formulas Used:
Einstein's famous equation connecting matter and energy states that
Using Planck's theory which states every quantum of a wave has a discrete amount of energy given by Planck's equation
The value of the planck's constant is given by
Because physical particles do not travel at the speed of light, de Broglie substituted v for the particle's velocity for the speed of light (c)
We can solve the equation (1) by replacing c with v.
The LHS of both equations (2) and (3) is clearly the same (i.e., energy E). As a result, the RHS of both equations may be equaled and will be equal.
The above equation is the necessary expression for the de Broglie wavelength of matter waves.
Hence, the correct answer is option 1.
Watch 3-min video & get full concept clarity