MCQ
A wire has a non-uniform cross-section as shown in figure.A steady current flows through it. The drift speed of electrons at points $P$ and $q$ is $v_P$ and $v_Q$.
- A$v_P = v_Q$
- B$v_P < v_Q$
- ✓$v_P > v_Q$
- DData insufficient
✓
Answer
Correct option: C.
$v_P > v_Q$
c
The drift speed of electrons is inversely proportional to the radius of cross section. Thus here the cross sectional area at point $P$ is smaller than the cross sectional area at point $Q$. Hence, the drift velocity is large for smaller area and small for larger area. The drift speed will relate as per the relation given below
The drift speed of electrons is inversely proportional to the radius of cross section. Thus here the cross sectional area at point $P$ is smaller than the cross sectional area at point $Q$. Hence, the drift velocity is large for smaller area and small for larger area. The drift speed will relate as per the relation given below
$v_{P}>v_{Q}$
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