revision ch 1-3

An electric field at a point is defined as

• the total charge on a particle at that point

• the electric force per unit mass at that point

• the electric force per unit charge at that point

• the electric charge per unit mass of a point charge

Answer explanation

E=F/q

A strong electric field has its field lines ____________.

• close together

• far apart

• uneven

• in circles

Answer explanation

The closer the field lines with each other, the stronger the field

Which image is the electric field of a positive charge?

• 
• 

Coulomb is used to measure

• Electric current

• Electric potential

• Electric charge

• Electric resistance

The total electric potential energy a charge has depends on the voltage

• True

• False

Answer explanation

U=qV

Which of the following statements is TRUE about equipotential surfaces?

• The charge density is uniform

• The electric field at any point on the equipotential surface is zero

• No electric potential difference between 2 nearby equipotential surfaces

• No work is done to move a charge along an equipotential surface

Principle of conservation of charges states that

• the total charge in an isolated system is constant

• the total force in an isolated system is constant

• the total electric potential in an isolated system is constant

What is Coulomb's law useful for?

• To make my life more difficult

• Calculate the force acting in a pair of point charges

• Calculate the energy acting in a pair of point charges

• Calculate the charge acting in a pair of point charges

Answer explanation

Coulomb's Law states that F=kQq/r^2

Why is the graph shaped as in the figure?

• because force F is directly proportional to the product of charges

• because force F is inversely proportional to the square of the distance r

• because force F is directly proportional to the distance

• because force F is directly proportional to the square of the distance r

How can the strength of this electric field be decreased?

• use a higher voltage battery

• increase the distance between the parallel plates

• decrease the distance between the parallel plates

• make the parallel plates longer

Answer explanation

E=V/d, as d increases, E decreases