Question

a current of 4.8 A is flowing in a conductor . the no. of electrons/second moving through any cross-section normal to direction of flow is?

Answer 1

Q. No. 1 Current of 4.8 amperes is flowing through a conductor. The number of electrons
crossing a cross-section per second will be
Option 1 3 10 × 19
Option 2 7.68 10 × 21
Option 3 7.68 10 × 20
Option 4 3 10 × 20
Correct Answer 1
Explanation
I = n
t
∈
I 4.8 1 = = = 3 10 electrons
1.6 10
t
n
e
× ×
×
×
19
-19
Q. No. 2 An ionization chamber with parallel conducting plates as anode and cathode has
5 0 ×1 electrons and the same number of singly charged positi - T e ve ions per cm . h
7 3
electrons are moving at 0.4 m/s. The current density from anode to cathode is
4 A /m . The velocity of positive ions moving towards cath µ ode is 2
Option 1 0.4 m/s
Option 2 16 m/s
Option 3 Zero
Option 4 0.1 m/s
Correct Answer 4
Explanation I = ne(Vd)e + ne(Vd)p
4 10 = 5 10 10 1.6 15 0.4 + 5 10 10 1.6 10 (V ) × × × × × × × × × × × -6 7 6 19 7 6 -19
d p
4 10 - 3.2 10 (V ) =
8 10
× ×
×
-6 -6
d p -6
= 0.1m/s
Q. No. 3 Which of the adjoining graphs represents ohmic resistance