Last updated on June 25th, 2023 at 02:30 pm
In this post, you will find solved Numericals on drift velocity for class 12. These numerical problems are based on the drift velocity of electrons and electric current.
( see the derivation of electric current and drift velocity equation )
Electric Current I = nAve
Mean drift velocity v = I /[nAe]
where A = area of cross-section of the conductor, n = number of electrons per cubic meter, e = charge on each electron, and v = drift velocity of the electron.
Numericals on Drift Velocity for Class 12 [solved]
1 ] A copper wire has a cross sectional area of 7.85 x 10-7 m2. The number density of copper is 8.5 x 1028 m-3. Calculate the mean drift velocity of the electrons through the wire when the current is 1.4 A.
The equation to use: I = nAve ( see the derivation of the drift velocity equation )
=> mean drift velocity = v = I/(nAe)…. ……… (1)
As per the problem statement, A=7.85 x 10-7 m2
n=8.5 x 1028 m-3
and I = 1.4 A
We know, e=1.6 x 10-19
Putting all the values in equation 1, we will get:
v= 1.31 x 10-4 m/s
Drift velocity Numerical Extra Questions as exercise
Now solve the following numerical problems using the same formula.
Take Away | Suggested reading
Here we have solved numerical problems on the drift velocity of electrons and electric current.
You can go through the following related and suggested posts for a better understanding of the topic.