Current Electricity Charging Discharging Of Capacitors Question 656
Question: Two wires each of radius of cross section r but of different materials are connected together end to end (i.e. in series). If the densities of charge carriers in the two wires are in the ratio 1:4, the drift velocity of electrons in the two wires will be in the ratio
Options:
A) 1 : 2
B) 2 : 1
C) 4 : 1
D) 1 : 4
Show Answer
Answer:
Correct Answer: C
Solution:
[c] Two wires carry the same current $ I=n _{1}eA,Vd _{1}=n _{2}eAVd _{2} $ So $ n _{1}Vd _{1}=n _{2}Vd _{2} $ or $ \frac{Vd _{1}}{Vd _{2}}=\frac{n _{1}}{n _{2}}=4\Rightarrow Vd _{1}:Vd _{2}=4:1 $
BETA
