Question

what is the force between two small charge Spheres having charges 2×10^-7C and 3×10^-7C placed 30 cm apart in air .
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Answer 1

$\bigstar$ Given:

• Charge on the 1st sphere $\sf =2 \times 10^{-7} C$
• Charge on the 2nd sphere $\sf =3 \times 10^{-7} C$
• The distance between two charges = 30 cm

$\bigstar$ To Find:

• The force between the charges.

$\bigstar$ Solution:

According to the given information,

The Charge on the 1st sphere and 2nd sphere is $\sf q_1=2 \times 10^{-7}C$ and $\sf q_2=3 \times 10^{-7 }C$

The distance between two charges is given by r = 30 cm = 0.3 m

The electrostatic force between the spheres is given by the relation:

$\sf F=\dfrac{1}{4\pi \epsilon_0} .\dfrac{q_1 \: q_2}{r^{2} }$

Now, here

$\sf \epsilon_0=$ Permittivity of free space

And,

$\sf \dfrac{1}{4\pi \epsilon_0} =9 \times 10^{9} \: Nm^{2}C^{-2}$

Force, F $\sf =\dfrac{9 \times 10^{9} \times 2 \times 10^{-7}}{(0.3)^{2}}=6 \times 10^{-3} N$

The force between the charges will be repulsive as they have the same nature.

$\bigstar$ Points to Note:

➤ Electrostatics deals with the study of forces, fields and potentials arising from static charges.

➤ The three fundamental properties of the electric charge are Quantization, Additive and Conservation.

➤ Coulomb’s Law consists of constant terms which are also called a constant of proportionality and is represented by ‘k’