Name: Continuous Charge Distribution
Uploaded: 2019-07-19
Duration: 5 min 39 s
Description: This video will help us understand the necessity of continuous charge distribution and learn about the concept of linear charge density. Learn more.

Question

(a) A copper sphere of mass

2 g

contains nearly

2 \times 10^{22}

atoms. The charge on the nucleus of each atom is

29 e

. What fraction of the electrons must be removed from the sphere to give it a charge of

+ 2.9 μ C

?
(b) What is an electric line of force? What is its importance?

Accepted Answer

(i) Given,

Charge of each nucleus $= 29 e$

Net charge $2 g$ sphere $= (29 e) \times (2 \times 10^{22}) = 5.8 \times 10^{23} e$

No.of electrons on sphere $= 5.8 \times 10^{23}$

No.of electrons removed to give $2.9 μ C$ charge $= (\frac{q}{e}) = [\frac{(2.9 \times 10^{- 6})}{1.6 \times 10^{- 19}}] = 1.25 \times 10^{13}$

Therefore, fraction of electrons removed $= [\frac{(1.25 \times 10^{13})}{(5.8 \times 10^{23})}] = 2.16 \times 10^{- 11}$

(ii) An electric line of force is an imaginary straight or curved path along which a small positive test charge is supposed to move when free to do so. The tangent at a point on an electric line of force gives the direction of the resultant electric field at that point. The relative closeness of electric lines of force in a certain region provides us an estimation of the electric field strength in that region.

Importance :- Drawing electric lines of force helps us to visualise to some extent the electric field in some region of space. Of course lines of force can only give us partial information about the nature of the electric field produced by given sources, but still be valuable. While we could put an arrow on each line of force to indicate the direction of electric vector at each point on it, the line cannot indicate the magnitude of the electric vector.

(a) A copper sphere of mass $2 g$ contains nearly $2 \times 10^{22}$ atoms. The charge on the nucleus of each atom is $29 e$ . What fraction of the electrons must be removed from the sphere to give it a charge of $+ 2.9 μ C$ ?
(b) What is an electric line of force? What is its importance?

Important Questions on Electric Charges and Fields

Learn and Prepare for any exam you want !

(a) A copper sphere of mass 2 g contains nearly 2×1022 atoms. The charge on the nucleus of each atom is 29 e. What fraction of the electrons must be removed from the sphere to give it a charge of +2.9μC ? (b) What is an electric line of force? What is its importance?

Important Questions on Electric Charges and Fields

Learn and Prepare for any exam you want !

(a) A copper sphere of mass $2 g$ contains nearly $2 \times 10^{22}$ atoms. The charge on the nucleus of each atom is $29 e$ . What fraction of the electrons must be removed from the sphere to give it a charge of $+ 2.9 μ C$ ?
(b) What is an electric line of force? What is its importance?