electric current and ohmic resistance

Question 1

diff electric current

Answer 1

it is the flow of electric charges between two terminals of condctor if there is electric potential diffrence between its terminals

Question 2

tell me about the dirction of electric current

Answer 2

coventional current real electron current

Question 3

diff convential current

Answer 3

it is the flow of electric charges from + to —

Question 4

diff real electron current

Answer 4

it is the flow from _ to +

Question 5

diff ohmic resistance

Answer 5

it is a type of opposition against the flow of electric charges duto to the firiction between the electron and moleculs of conductor that causes loss of electric charges in form of thermal energy

Question 6

passing of electric current in conductor is associated with harmfull effect and useful effect tell me about them

Answer 6

1. in some electric instrument which causes loses in electric energy in form of thermal energy that causes damage of wires and the devices when the temperature increases
2. in some instrumrnt designed for converting the electric energy into heat energy

Question 7

ohmic resistance depends on

and the rule and unit

Answer 7

1. length of conductor R&L at constant other factor
2. cross sectional area of the conductor R &1/A
3. kind of material
4. temperature
5. R=p x L / A
6. OHM ,

Question 8

diff specific resistance ( resistivity )

Answer 8

it is the resistance of conductor of the material of length 1 m and cross sectional area 1 m2 at constant temperature or 0C

Question 9

spesific resistance depends on

and rule and unit

Answer 9

1. kind of material
2. temperature

P = RxA / L

Question 10

the resistivity increases if

Answer 10

the conductor has hig tempretre and high conctentration of free electron

Question 11

diff conductivity

Answer 11

it is the resiprocal of the resistivity of the material

Question 12

conductivity depends on

and rule and unit

Answer 12

1. kind of material
2. temperature

1 / P OR L/RxA

Question 13

he conductivity of conductor increace by

and decreases by

Answer 13

1. increasing of free electron
2. increasing of emprere in conductor

Question 14

some materials conduct electricity while others are considered insulators GR

Answer 14

1. good conductor has high concentration of free electrons like metals
2. while insulator has no free electron like plastic

Question 15

the electrical conductivity of different materials is different

Answer 15

duo to the concentration of free electrons

Question 16

copper has high conductivity

Answer 16

because it has high concentration of free electrons

Question 17

the resistance of wire and its resistivity increase as the temperature increases GR

Answer 17

because increasing the temperature will increase the average kinetic energy of molecules of the conductor so its firiction with charges increases

Question 18

the specific resistance and conductivity are carctrized in matter GR

Answer 18

bec they depends on kind of material and temperature only

Question 19

the temperature of a wire increases when the electric current pass through it GR

Answer 19

duto the friction force between the moulcules of the conductor and the electron ( ohmic reistance ) that causes loses in electric energy in form of thermal energy

Question 20

It is advisple to use thick wire of copper when a strong current passes GR

Answer 20

bec it has low ohmic resistance and copper has high conductivity and low resistivity also thick wire has low resistance [R=PxL\A ⇒R&1\A] that will minmize loses in electric energy inform of thermal energy to prevent melting of wire

Question 21

conductivity of mercury = 106

Answer 21

106 is the recprocal of the resistivity of the material of mercury

Question 22

what is the rule of ratio in the ohmic resisance relathion

Answer 22

R₁ / R₂ = P₁ / P₂ x L₁ / L₂ x A₂ / A₁

Question 23

what meant by specific resistance of cupper = 1.77

Answer 23

the resistance = 1.77 when lingth = 1m and cross sectional area = 1 m² at given temperture

Question 24

what is dosnot change in the wire when it reformed

and if the length doubled and why

Answer 24

1. resistvity and conducitvty
2. if length is doubled that mean cross section area halved
3. because v_ol is constant ( V_ol = A x L )

Question 25

the resistance doubled what will happen to current

the current doubled what will happen to resistance

Answer 25

1. decresed to half
2. no thing

Question 26

what is the ratio of relation of ohmic resistance

and if i tell you the wire is reformed that mean and why

Answer 26

R1\R₂=P₁\P₂ x L₁\L₂ x A₁\A₂

P1 = P2

if the length doubled the area halved at constant V_ol

due to the relation V_ol = LxA