chapter one

Answer 6

1.

Answer 7

1.

Answer 9

1.

Question 11

the electrical conductivity of different materials is different

Answer 11

duo to the concentration of free electrons

Question 12

give reasons some materials conduct electricity while others are considered insulators

Answer 12

good conductor has a high concentration of free electrons like metals while insulators has no free electron like plastic

Question 13

give reasons the electrical conductivity of different materials is different

Answer 13

duto the concentration of the free electrons

Question 16

give reasons copper has a high condictivity

Answer 16

bec it is has a high constrition of free electron

Question 21

diff electric sourse

Answer 21

source of electromotive force to make electric potential defference between the terminal of conductor

Question 22

diff wire

Answer 22

to conduct electrical charges through the closed circuit

Question 23

diff key switch

Answer 23

to switch on or off the circuit

Question 24

diff ammeter

Answer 24

instrument connected in series to measure the elerctric current intensity through the circuit

Question 25

dif voltmeter

Answer 25

instrument connected in parallel between two points to measure the electric potential differennce between this point

Question 26

fixed resistance

Answer 26

it is consumes the electric energy in form of thermal energy

Question 27

Rheostat

Answer 27

to control the total resistance through the whole circuit

Question 29

diff potential difference

Answer 29

it is the work done to transfer a unit of charge between these two points

Question 30

diff ohms law

Answer 30

it is the current intensity in a conductor is directly proportional to the potential difference across its terminals at constant temperature

Question 31

diff couloum

Answer 31

cc

Answer 35

check it

Question 43

physical quantity , equivlant unit volt / amp J / C-1 amp . sec ohm . m v . m/A ohm -1 . m-1

Answer 43

C

Question 46

a wire of resistance 2 ohm carry 3 amp if the electric current in the same wire is increased to be 6 amp the resistance of the wire be

Answer 46

same as it

Question 47

series connection of resistors lead to in the total resistance

Answer 47

increase

Question 48

series connection of resistors lead to in the total resistance

Answer 48

decrease

Question 49

the lowest equivalent resistance for some resistance is on joining them

Answer 49

parallel

Question 50

the greatest equivalent resistance for some resistance is on joining them

Answer 50

series

Question 51

when the length of copper wire is doubled and itis cross section decreases to half it is resistance

Answer 51

g

Question 52

wire of resistance if its length is doubled and its radius is decreased to half its value sot the resistance

Answer 52

g

Question 53

wire of resistance if its length is doubled and its radius is decreased to half its value sot the specific resistance

Answer 53

g

Question 54

when the radius of wire increased to double its value while the length decreased 1 / 4 itis value so it is conductivity

Answer 54

g

Question 55

cylindral rod of cupper is reformed which its length to 3 times its value then its resistance become its value

Answer 55

g

Question 56

a conductor of uniform cross - section it is length 20 m and it is resistance 108 ohm antother conductor of the same matriel itis length 5 m and cross - section area = three times the cross sectinol area of the first . the resistance of the second =

Answer 56

g

Question 57

a wire resistance and another of similar material and length but of the diameter 2/3 of the diameter of the first so resistance of the second wire =

Answer 57

g

Question 58

a wire resistance and another of half lengthifthe diameter 2nd wire = the radius of the of the first and itis resistivity is 4/3 so resistance of the second wire =

Answer 58

g

Question 59

explain an experiment to determine the equivlant resistance of resistors connected in series

Answer 59

p 22 guide ans

Question 60

explain an experiment to determine the equivlant resistance of resistors connected in parallel

Answer 60

p 23 guide ans

Question 66

EXPERMENT of ohms law for closed circuit

Answer 66

p 47

Question 69

give reason the potential difference between the terminals of the cell is not the same as its E . M . F

Answer 69

because work is lost to overcome causes drop in voltage (Ir) so the external voltage is always smaller than E . M . F by the value of ( Ir ) ( V=VB - Ir )

Question 70

the resistavity of incresing by increacing

Question 71

a fuse supports current 1 amp , is placed in a circuit contains a battery of e.m.f , the smallest resister connected in series with the circuit to avoid melting fuse

Answer 71

R = V / I R = 6 I = V / R = 1 the fuse not melting , elshrt en my3dysh ay current akbr mn elmdhwlk