Electricity and circuits

Question 1

What is a Ohmic conductor

Answer 1

those where the resistant remains constant as the current is varied

Question 2

What is a non- ohmic conductor

Answer 2

Do not have a constant relationship between voltage and current

Question 3

Equations used for ohmic conductors

Answer 3

V= I x R for the gradient

Question 4

What is ohms law

Answer 4

I = V/R

“ the voltage is directly related to the current, when the resistance is constant”

Question 5

Factors that effect electrical resistance

Answer 5

• size of potential difference across the ends of the wire
• length of the wire
• temperature of the wire
• cross section of the wire

Question 6

What is resistance

Answer 6

The measure of how hard it is for electrons to flow through a particular material

Question 7

What is V= I x R

Answer 7

V= Voltage (volts)
I= Current (amps)
R= Resistance (ohm)

Question 8

All electrical equations

Answer 8

V= E/Q
I = Q/T
E = VxIxT
P = E/T
q = n x e
V = I x R

V= voltage (V)
q = charge (C)
R= resistance (ohms)
T= time (seconds)
I = current (A)
E/W = energy/work (joules)
P = power (watts)
Q = energy

Question 9

What is direct current (DC)

Answer 9

The flow of charge is always in one direction

e.g: current from a battery

Question 10

What is alternating current (AC)

Answer 10

The flow of charge alternates back and forth

Question 11

What is Current

Answer 11

The rate at which charge flows through a surface

Same flow as the positive charge

Question 12

What is current measured in

Answer 12

amps (A)

Question 13

What is the equation I = Q/T

Answer 13

I = current (A)
Q= charge (C)
T= time (Seconds)

Question 14

3 parts of a basic circuit

Answer 14

• A source of energy
• A closed path
• a device which uses the energy

Question 15

Potential difference (voltage) equation

Answer 15

V = E/Q

V= voltage
Q= charge
E= work/ enegry

Question 16

q = n x e

Answer 16

Charge = number of eletrons x charge of eletrons

Question 17

What is a voltmeter

Answer 17

measures potential difference through a circuit

Question 18

What is an ammeter

Answer 18

measures current through a circuit

Question 19

What is Ohms law

Answer 19

V = I x R

Question 20

equations for series resistors

Answer 20

It = I1 = I2 ect
Vt = V1 + V2 ect
Rt = R1 + R2 ect

Question 21

equations for parallel resistors

Answer 21

Rt(-1) = (R1 + R2)-1      (1 over resistance)
Vt = V1 = V2
It = I1 + I2