Summary

Question 1

Lightning and ___________ are two common phenomena in our hot and humid atmosphere in Nigeria.

Answer 1

Thunder

Question 2

___________ demonstrated as long ago as 1752 that thunder clouds are charged with electricity.

Answer 2

Benjamin Franklin

Question 3

The charged clouds when discharged in the atmosphere give rise to a great spark referred to as _____________

Answer 3

Lightening

Question 4

The amount of electric current during the discharge of charged clouds is____________

Answer 4

20KA

Question 5

The ____________which gives rise to lightning produces a great amount of heat.

Answer 5

Electric discharge

Question 6

In a fraction of a second, ___________ rises to about 150000C

Answer 6

Temperature

Question 7

When the sound is reflected by clouds, hill or any other obstacle, we hear the roaring of____________

Answer 7

Clouds

Question 8

The forces between electric charges are very large.

Answer 8

True

Question 9

The force responsible for holding electrons to nuclei to form atoms and for holding the groups of the atoms together to form molecules, solids and liquids is called___________

Answer 9

Electrostatic force

Question 10

Electrostatic force is also called___________

Answer 10

Electric force

Question 11

The study of static charges is known as____________

Answer 11

Electrostatic

Question 12

Types of electric charge

Answer 12

positve and negative

Question 13

Who discovered that other substances exhibit the same effect and that the magnitude of the effect is roughly proportional to the area of the surface rubbed?

Answer 13

William Gilbert

Question 14

___________ discovered that there are two kinds of electricity.

Answer 14

Du Fay (1745)

Question 15

Two ebonite rods when rubbed with fur exert a ____________on each other

Answer 15

Force of repulsion

Question 16

The two kinds of electricity can neutralize each other‟s effect

Answer 16

True

Question 17

___________ rubbed with silk is said to have a positive charge

Answer 17

Glass

Question 18

Ebonite rubbed with fur has__________ charge.

Answer 18

Negative

Question 19

What is the law of force between charges

Answer 19

The law of force between charges states that like charges repel, unlike charges attract

Question 20

The proton and neutron in the nucleus are held together very tightly by___________.

Answer 20

Nuclear force

Question 21

The force holding electron to the atomic nucleus is much weaker than the nuclear force.

Answer 21

True

Question 22

This process of charging the bodies by means of rubbing them together is called__________

Answer 22

Charging by friction

Question 23

SI stands for___________

Answer 23

System International

Question 24

Electric charge is measured in __________

Answer 24

Coulombs

Question 25

The SI symbol for coulombs is___________

Answer 25

C

Question 26

Coulombs is defined in terms of___________

Answer 26

Ampere

Question 27

A ___________ is the quantity of charge flowing per second through a conductor in which there is a steady current of 1A

Answer 27

Coulomb

Question 28

The algebraic sum of the equal and opposite charges on two bodies is__________

Answer 28

Zero

Question 29

___________ is a conserved quantity

Answer 29

Electric charge

Question 30

What is the charge conservation law

Answer 30

The charge conservation law states that the total electric charge in an isolated system, that is, the algebraic sum of the positive and negative charge present at any time does not change.

Question 31

The smallest charge that is possible to obtain is that of an___________

Answer 31

electron or proton

Question 32

The magnitude of the forces between charged spheres was first investigated quantitatively in 1785 by___________

Answer 32

Charles Coulomb

Question 33

The permittivity of a vacuum is denoted by ______

Answer 33

The permittivity of a vacuum is denoted by εo (pronounced as epsilon naught) and is called the permittivity of free space

Question 34

An ____________is a region where an electric charge experiences a force

Answer 34

Electric field

Question 35

Electric field is measured in ___________

Answer 35

Newtons Coulomb

Question 36

An electric field can be represented by ___________or lines of force

Answer 36

Electric field lines

Question 37

A ___________ is defined as a path along which a free positive point charge would travel in an electric field

Answer 37

Field line

Question 38

___________ law expresses the relation between an electric charge and the electric field that it sets up

Answer 38

Gauss’s law

Question 39

Gauss‟s law is a consequence of ____________ law.

Answer 39

Coulomb’s

Question 40

The number of the lines of force crossing any surface depends on ____________factors

Answer 40

Three factors namely: ∙ the field strength, E ∙ the surface area, S ∙ the orientation of the surface relative to the electric field

Question 41

____________ states that the electric flax through the sphere is proportional to the charge and is independent of the radius of the surface

Answer 41

Gauss’s law

Question 42

Gauss‟s law applies to any hypothetical closed surface called a____________.

Answer 42

Gaussian surface

Question 43

___________ at a point in a field can be defined as the work done per unit charge moving from infinity to the point.

Answer 43

Electric potential

Question 44

The unit of Electric potential is______

Answer 44

joule per coulomb (JC^-1) or volts (V).

Question 45

Electric potential is a property of _____ and is a scalar quantity

Answer 45

a point in a field

Question 46

A pair of equal and opposite charge, ±q, separated by a vector distance a is called

Answer 46

a dipole.

Question 47

If the product q1 q2 is negative (unlike charges) the potential energy is _____

Answer 47

negative

Question 48

A negative potential energy means that work has to be done to_____

Answer 48

pull the charges away from each other.

Question 49

The unit of C is coulomb per volt (CV-1) also known as ______

Answer 49

a Farad (F)

Question 50

Relative permittivity has no units

Answer 50

True

Question 51

When a dielectric material is subjected to a sufficiently strong electric field it becomes a conductor. This phenomenon is known as ___________

Answer 51

Dielectric breakdown

Question 52

Capacitors may be classified into two broad groups _____ and _______

Answer 52

fixed and variable

Question 53

An electrolytic capacitor consists of two electrodes of aluminum called_____ and _______

Answer 53

the positive and the negative plates

Question 54

There are two types of electrolytic capacitors ________ and _________

Answer 54

the wet type and the dry type.

Question 55

The ___________of a capacitor is a measure of its ability to store electric charge.

Answer 55

Capacitance

Question 56

A __________ is a device which can store electric charge

Answer 56

Capacitor

Question 57

The ___________is defined as that direction in which a positive charge moves.

Answer 57

Direction of current

Question 58

___________ is defined as the current per unit area perpendicular to the velocity of the charge carriers

Answer 58

Current density

Question 59

The unit of resistance is ____________

Answer 59

volt per ampere ( 1 VA-1 ) or 1 Ohm ( IΩ )

Question 60

A perfect conductor has __________resistivity

Answer 60

Zero

Question 61

A perfect insulator an __________ resistivity

Answer 61

Infinite

Question 62

The resistivity of all metallic conductors increases with increasing temperature

Answer 62

True

Question 63

__________ is a measure of energy transfer

Answer 63

Work