Maryam sets up a current , I = 0.80 A , across a bulb in an experiment.
What is the magnitude of net charge , q , flowing through the bulb in time , t = 5.0s ?
q = ( ? ) C
Answers
Answer:
Explanation:
Electricity
Electric Current & Circuit
Electric Current: The flow of electric charge is known as electric current. Electric current is carried by moving electrons through a conductor.
By convention, electric current flows in opposite direction to the movement of electrons.
Electric Circuit: Electric circuit is a continuous and closed path of electric current.
Expression of Electric Current: Electric current is denoted by letter ‘I’. Electric current is expressed by the rate of flow of electric charges. Rate of flow means the amount of charge flowing through a particular area in unit time.
flow of electric charge
Fig: Conventional Flow of Electric Charge
If a net electric charge (Q) flows through a cross section of conductor in time t, then;
Electric Current
(
I
)
=
Net charge
(
Q
)
Time
(
t
)
Or,
I
=
Q
t
Where,I is electric current,Q is net charge and t is time in second.
SI unit of Electric Charge and Current:
SI unit of electric charge is coulomb (C).
One coulomb is nearly equal to
6
×
10
18
electrons. SI unit of electric current is ampere (A). Ampere is the flow of electric charges through a surface at the rate of one coulomb per second. This means if 1 coulomb of electric charge flows through a cross section for 1 second, it would be equal to 1 ampere.
Therefore;
1
A
=
1
C
1
s
Small quantity of Electric Current: Small quantity of electric current is expressed in milliampere and microampere. Milliampere is written as mA and microampere as μA
1mA (milliampere)
=
10
−
3
A
1μA(microampere)
=
10
−
6
A
Ammeter: An apparatus to measure electric current in a circuit.
Solution: Given, electric current (I) = 5 A
Time (t) = 5 minute
=
5
×
60
=
300
s
Electric charge (Q) =?
We know;
I
=
Q
t
Or,
Q
=
I
×
t
Or,
Q
=
5
A
×
300
s
=
1500
C
Example 2: If a current of 2 ampere is drawn for 1 hour through the filament of a bulb, find the amount of electric charge flowing through the circuit.
Solution: Given, electric current (I) = 2 A
Time (t) = 1 hour
=
1
×
60
×
60
s
=
3600
s
Electric charge (Q) =?
We know that
Q
=
I
×
t
Therefore,
Q
=
2
A
×
3600
s
=
7200
C
Example 3: In how much time 6000 coulomb of electric charge will flow, if an electric current of 10 A is drawn through an electric motor?
Solution: Given, electric charge (Q) = 6000 C
Electric current (I) = 10 A
Time (t) = ?
We know;
I
=
Q
t
Or,
t
=
Q
I
Or,
t
=
6000
C
10
A
=
600
s
Or,
t
=
10
min
Example 4: If an electric charge of 900 C flows through an electric bulb for half an hour, find the electric current drawn by the filament.
Solution: Given, electric charge (Q) = 900 C
Time (t) = Half an hour = 30 m
=
30
×
60
=
1800
s
Electric current (I) =?
We know;
I
=
Q
t
Or,
I
=
900
C
1800
s
=
0.5
A
Example 5: If an electric charge of 15000 C flows through an electric iron for 5 minute, find the electric current drawn by filament of electric iron.
Solution: Given, electric charge (Q) = 1500 C
Time (t) = 5m
=
5
×
60
=
300
s
Electric current (I) =?
We know;
I
=
Q
t
Or,
I
=
1500
C
300
s
=
5
A