Current Electricity Worksheets
Worksheet3.01
(Basics of Electric Current)
General Instructions
CBSE, NEET, PSEB, HSEB etc.

Ques01:
A current of 7 A is maintained in a wire for 40 s.
(i) How much current will flow through the wire?
(ii) How many electrons flow through the wire in the given time?
Ques02:
10^{20} electrons each having a charge of 1.6 x 10^{19} C pass from a point A towards another point B in 0.1 s.
(i) Calculate the current in ampere.
(ii) What is the direction of current?
Ques03:
If 2.25 x 10^{20} electrons pass through a wire in one minute, find the magnitude of the current flowing through the wire.
(PSEB 2002)
Ques04:
How many electrons per second flow through the crosssection of a conductor so that the conductor carries a current of 1 ampere?
OR
Show that one ampere is equivalent to a flow of 6.25 x 10^{18} elementary charges per second.
(CBSE D 1992)
Ques05:
How many electrons pass through a wire in 1 minute if the current passing through the wire is 300 mA?
(PSEB 2002)
Ques06:
Find the rate of electrons passing through a wire if the wire carries a current of 3.2 A.
Ques07:
A point charge q moves in a circle of radius R at a constant speed v. What will be the current associated with this uniform circular motion?
Ques08:
In a hydrogen atom, an electron revolves around the nucleus in a circular orbit at the rate of 10^{15} revolutions per second. Calculate the equivalent current.
(ROORKEE 1984)
Ques09:
In an atom, an electron revolves around the nucleus in a circular orbit at the rate of 10^{15} revolutions per second. Calculate the equivalent current.
Ques10:
The amount of charge passing through crosssection of a wire is q(t) = 5t^{2} + 3t + 1. Find the value of current at t = 5 s.
Ques11:
Charge flowing through a crosssection is given as function of time as q = 2t^{2} + 3. Find the value of current at t = 2 s.
Ques12:
The current through a wire depends on time as I = I_{o} + αt where I_{o} = 10 A and α = 4 As^{1}. Find the charge that flows across a section of the wire in 10 seconds.
Ques13:
The current through a wire depends on time as I = 4 + 3t + 2t^{2}. Find the charge that flows across a section of the wire in 6 seconds.
Ques14:
A current flowing through a wire depends on time as I = 3t^{2} + 2t + 5. Find the charge flowing through the crosssection of the wire in time from t = 0 to t = 2 s.
Ques15:
The following figure shows a plot of current I through the crosssection of a wire over a time interval of 10 s. Find the amount of charge that flows through the wire during this time period.
(CBSE 2015 C)
Ques16:
The current I in a circuit varies with time t as per the relation I = 3 + 2t. Find constant current which would send the charge equivalent to the time interval t = 0 to t = 4 s.
ANSWER KEY
1. 280 C ; 1.75 x 10^{21} electrons
2. 160 A ; Direction of current is from B to A
3. 0.6 A
4. 6.25 x 10^{18} electrons
5. 1.125 x 10^{20}
6. 2 x 10^{19}
7. qv/2πR
8. 1.12 mA
9. 0.16 mA
10. 53 A
11. 8 A
12. 300 C
13. 222 C
14. 22 C
15. 37.5 C
16. 7 A
MCQs Quiz
Quiz on Basics of Electric Current
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