Coulomb's Law and Torsion Balance

The video tutorial explains Coulomb's torsion balance, an instrument invented by Charles Augustine Coulomb to measure electric forces between charged objects. It describes the components of the torsion balance, including the glass case, torsion head, and needle. The tutorial details Coulomb's experiment, where he observed the interaction between charged bodies and derived Coulomb's Law. This law states that the force between two point charges is directly proportional to the product of their magnitudes and inversely proportional to the square of the distance between them.

What is the primary purpose of Coulomb's Torsion Balance?

• To measure gravitational forces

• To verify the quantitative law of interaction between electrical charges

• To measure magnetic forces

• To calculate the speed of light

Which component of the torsion balance is used to measure the torsion produced in the fiber?

• The degree scale on the glass case

• The horizontal needle

• The brass disc

• The torsion head

Which material is used for the horizontal needle in Coulomb's Torsion Balance?

• Brass

• Glass

• Lac

• Steel

What is the role of the torsion fiber in Coulomb's Torsion Balance?

• To adjust the height of the needle

• To hold the glass case

• To suspend the horizontal needle

• To measure the electric charge

What happens when the brass disc touches a charged sphere in Coulomb's experiment?

• The disc and sphere attract each other

• The disc loses its charge

• The disc remains stationary

• The disc and sphere repel each other

What did Coulomb observe when both the disc and sphere were without charge?

• The disc attracted the sphere

• The thread remained stationary

• The thread moved

• The needle oscillated

How did Coulomb reduce the charge of the sphere in his experiment?

• By heating the sphere

• By placing it in contact with another sphere of the same size

• By exposing it to sunlight

• By immersing it in water

What is the relationship between the force and the distance between two charges according to Coulomb's Law?

• Inversely proportional to the distance

• Inversely proportional to the square of the distance

• Directly proportional to the distance

• Directly proportional to the square of the distance

What is the value of the electrostatic force constant K in Coulomb's Law?

• 1 x 10^9

• 9 x 10^9

• 1 x 10^6

• 9 x 10^6

What is the mathematical expression for the force between two point charges according to Coulomb's Law?

• F = K * q1 * q2

• F = K * q1 * q2 / r

• F = K * q1 * q2 / r^2

• F = q1 * q2 / r^2