Two identical copper spheres are separated by 1m in vaccum .how many electrons would have to be removed from one sphere and added to the other so that they now attract each other with a force of 0.9 N?

Question

Answer

For a force 0.9 to act bet 2spheresF = k q^2/r^20.9=9×10^9 × q^2/1^2q^2= 0.9/9×10^9 q^2=10^-10Cq = 10^-5Cthen q=ne so n= 10^-5/1.6×10^-19 n=6.25×10^13

Answer

We know force =k q¹ q²/r² substituting in this we get answer as. 6.25*10²²

Answer

Calculating the number of electrons to be transferred:

To determine the number of electrons that need to be transferred from one sphere to the other in order for them to attract each other with a force of 0.9 N, we can use the concept of electric force.

Electric force formula:
The electric force between two charged objects can be calculated using Coulomb's law:
$$ F = \frac{k \cdot |q_1 \cdot q_2|}{r^2} $$
Where:
- $ F $ is the electric force,
- $ k $ is the Coulomb constant ($ 8.99 \times 10^9 N m^2/C^2 $),
- $ q_1 $ and $ q_2 $ are the charges on the spheres,
- $ r $ is the distance between the spheres.

Calculating the initial charge:
Since the spheres are initially neutral, the total charge is distributed equally on both spheres. Let $ q $ be the charge on each sphere.

Calculating the force when charges are equal:
When the charges on both spheres are equal, the force between them can be calculated as:
$$ F = \frac{k \cdot |q^2|}{r^2} $$

Calculating the charge required for a force of 0.9 N:
Given that the force is now 0.9 N, we can set up the equation:
$$ 0.9 = \frac{k \cdot |q^2|}{1^2} $$
Solving for $ q $, we find the charge on each sphere.

Calculating the number of electrons:
Once we find the charge on each sphere, we can calculate the number of excess or deficit electrons required to achieve this charge difference between the spheres. Each electron carries a charge of $ 1.6 \times 10^{-19} C $, so dividing the total charge by this value gives us the number of electrons to be transferred.

By following these steps, we can determine the exact number of electrons that need to be transferred between the spheres to achieve the desired force of 0.9 N.

Similar JEE Doubts

two identical spheres having charges +10micro c and -90 micro c attract each other with a force F. if they are kept in contact and then separated by the sane distance, the new force between them is. a. F/6 b. 16F c.16F/9 d.9F

Top Courses for JEEView all

Physics for JEE Main & Advanced

Mock Tests for JEE Main and Advanced 2025

Chemistry for JEE Main & Advanced

Mathematics (Maths) for JEE Main & Advanced

Chapter-wise Tests for JEE Main & Advanced

Top Courses for JEE

Top Courses for JEE

Suggested Free Tests

Related Content

JEE Courses

Mock Test Series

Past Year Papers

Additional Courses

Company