Current electricity

Question 1

electric field is in the direction of

Answer 1

1) opposite to electron flow
2) in the direction of current

Question 2

Ohm’s law

Answer 2

1)Ohm’s Law states that, “current through a conductor between two points is directly proportional to the voltage across two points.
2) V=IR
3)applicable only to ohmic conductor

Question 3

temperature dependence of resistivity

Answer 3

ρT = ρ0 [1 + a(T–T0)]

Question 4

Electrical Energy:

Answer 4

It is the amount of work done or energy consumed in a given amount of time
E = I^2Rt

Question 5

electromotive force

Answer 5

it is a work done by a source in taking a unit charge once around the complete circuit

Question 6

potential diiference

Answer 6

it is the workdone in moving a charge from one poinr to another point in a circuit

Question 7

terminal voltage

Answer 7

V = emf − Ir
r–>internal resistance

Question 8

current in circuit which has a battery of internal resistance ‘r’

Answer 8

I=emf/R+r

Question 9

If n, e, t, and m have their usual meanings, then the resistance of a wire of length l and cross-sectional area A is given by

Answer 9

r=ml /ne²tA
t–>relaxation time

Question 10

current density

Answer 10

j=neVd
where
j=I/A
n –> number of free electrons
e –> charge of electron
Vd –> drift velocity