Static & Direct Current Electricity (E1)

What is static electricity and how does it work?

• The flow of electric current through a conductor, typically involving a continuous movement of electrons.

• The energy produced by the movement of protons within an atom, causing a magnetic field.

• The build-up of electric charge on the surface of objects, which occurs when electrons are transferred from one object to another, often through friction.

• The result of chemical reactions that produce heat and light, similar to combustion.

What natural phenomenon is an example of static electricity discharge?

• Earthquake

• Tornado

• Lightning bolt

• Rainfall

What is shown in Figure 1.66?

• Magnetic field lines

• Radial electric field lines from an isolated point charge

• Gravitational field lines

• Thermal field lines

In the formula I = q/t, what does 'q' represent?

• Voltage

• Resistance

• Charge

• Power

Answer explanation

I=Current

t= time measured in seconds

q= charge in coulombs

What is the relationship between the force and the distance between two charged objects according to Coulomb's law?

• Directly proportional

• Inversely proportional

• No relationship

• Exponentially proportional

Answer explanation

When the value of one quantity increases with respect to decrease in other or vice-versa, then they are said to be inversely proportional. It means that the two quantities behave opposite in nature.

This means that as the distance ((r)) between the two charges increases, the force ((F)) decreases rapidly. Specifically, if the distance is doubled, the force is reduced to one-fourth of its original value. Conversely, if the distance is halved, the force increases to four times its original value. This inverse square relationship highlights how sensitive the force is to changes in distance between the charged objects.

What is the nature of the force between two unequal and opposite charges?

• Positive

• Neutral

• Negative

• Zero

Answer explanation

What is the value of the permittivity of free space (ε0)

What is the unit of distance in Coulomb's law?

• Newtons (N)

• Meters (m)

• Coulombs (C)

• Farads (F)

What is the equation for permittivity of free space (ε₀)?

• ε₀ = D/E

• ε₀ = E/D

• ε₀ = D²/E

• ε₀ = E²/D

Answer explanation

ε₀= permittivity of free space

D= Density

E= electric field strength

What does the variable 'V' represent in the formula E = V / d?

• Velocity

• Voltage

• Volume

• Viscosity