Electrostatics, Electric Field and Potential

These flashcards summarize key concepts from the lecture on electrostatics, electric fields, and potentials.

What is the ratio of the Coulomb electric force to the gravitational force between two electrons in vacuum?

The ratio can be determined using the formula for electric force and gravitational force.

If two coins with identical charges are 2.5m apart and one experiences a 3N force, how can we find the charge on each coin?

Use Coulomb's Law to solve for the charge.

What is the potential at a distance of 10cm from a charge of 3×10^{-5} C?

Calculate using the formula for electric potential.

How much work is required to carry a 0.02μC charge from r = 40cm to r = 5cm?

Calculate work done using the formula W = qΔV.

What is the potential V at a radius of 1.0 × 10^{-4} m from a tin nucleus with charge +40e?

Use the formula for potential due to a point charge.

If an electron falls through a potential rise of 100V, how can we find its final speed?

Use energy conservation principles relating potential energy to kinetic energy.

What is the potential at the center of a square with four corner charges of +2.5μC?

Calculate the contribution from each charge and sum them up.

At what point is the potential equal to zero between two point charges +q and -q separated by distance d?

The point where the potentials due to both charges cancel out.

How can a conductor be given a permanent positive charge?

By removing some electrons, leaving excess positive charge.

How can a gold leaf electroscope detect an unknown positive charge?

By observing the movement of the gold leaves when the charge is introduced.