Current Electricity Worksheets

 

Worksheet-3.01

(Basics of Electric Current)

 

General Instructions This worksheet belongs to the Chapter- Current Electricity This worksheet is based on the concept of- Basics of Electric Current The worksheet includes subjective questions from NCERT & different exams like- CBSE, NEET, PSEB, HSEB etc. The answer key is provided at the end to check your answers.

 

Ques-01:

 

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?

 

Ques-02:

 

10²⁰ 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?

 

Ques-03:

 

If 2.25 x 10²⁰ electrons pass through a wire in one minute, find the magnitude of the current flowing through the wire.

(PSEB 2002)

 

Ques-04:

 

How many electrons per second flow through the cross-section 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 10¹⁸ elementary charges per second.

(CBSE D 1992)

 

Ques-05:

 

How many electrons pass through a wire in 1 minute if the current passing through the wire is 300 mA?

(PSEB 2002)

 

Ques-06:

 

Find the rate of electrons passing through a wire if the wire carries a current of 3.2 A.

 

Ques-07:

 

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?

 

Ques-08:

 

In a hydrogen atom, an electron revolves around the nucleus in a circular orbit at the rate of 10¹⁵ revolutions per second. Calculate the equivalent current.

(ROORKEE 1984)

 

Ques-09:

 

In an atom, an electron revolves around the nucleus in a circular orbit at the rate of 10¹⁵ revolutions per second. Calculate the equivalent current.

 

Ques-10:

 

The amount of charge passing through cross-section of a wire is q(t) = 5t² + 3t + 1. Find the value of current at t = 5 s.

 

Ques-11:

 

Charge flowing through a cross-section is given as function of time as q = 2t² + 3. Find the value of current at t = 2 s.

 

Ques-12:

 

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.

 

Ques-13:

 

The current through a wire depends on time as I = 4 + 3t + 2t². Find the charge that flows across a section of the wire in 6 seconds.

 

Ques-14:

 

A current flowing through a wire depends on time as I = 3t² + 2t + 5. Find the charge flowing through the cross-section of the wire in time from t = 0 to t = 2 s.

 

Ques-15:

 

The following figure shows a plot of current I through the cross-section 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)

 

Ques-16:

 

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 10²¹ electrons

2. 160 A ; Direction of current is from B to A

3. 0.6 A

4. 6.25 x 10¹⁸ electrons

5. 1.125 x 10²⁰

6. 2 x 10¹⁹

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

 

Get Notes & other Study Material of the Chapter Current Electricity.