What are the advantages and disadvantages of membrane structures.pptx
Jasem Mohammed.pptx
1. Ministry Of Higher Education
Diyala University College Of Engineering
Department Of Power
Ohm’s Law
By:
Jasem Mohammed
Supervisor:
Dr. Ahmed
2. Indicator :
• To formulate the mulberry of electric
current strength inclosed series (the electric
current strength).
• To formulate the mulberry of electric
resistance strength series (the electric
resistance strength).
• To formulate the mulberry of tension in
simple closed series uses Kirchof Law II.
3. Ohm’s Law
Current through an ideal conductor is proportional to the
applied voltage – Conductor is also known as a resistor –
An ideal conductor is a material whose resistance does
not change with temperature For an ohmic device,
Voltage =Current* Resistance
V= I * R
V = Voltage (Volts = V) I = Current (Amperes = A)
R = Resistance (Ohms = Ω)
4. Current and Voltage Defined
Conventional Current: (the current in electrical
circuits) Flow of current from positive terminal to
the negative terminal. - has units of Amperes (A)
and is measured using ammeters.
Voltage: Energy required to move a charge from
one point to another. - has units of Volts (V) and
is measured using voltmeters. Think of voltage as
what pushes the electrons along in the circuit,
and current as a group of electrons that are
constantly trying to reach a state of equilibrium.
5. Ohmic Resistors
• Metals obey Ohm’s Law linearly so long as
their temperature is held constant
– Their resistance values do not fluctuate
with temperature
• the resistance for each resistor is a
constant
Most ohmic resistors will behave non-
linearly outside of a given range of
temperature, pressure, etc.
6. Voltage and Current Relationship for Linear Resistors
Voltage and current are linear when resistance is held constant.
7.
8.
9.
10.
11. R1 R2 R3 V I1 I2 I3
20 ohm 30ohm 40 ohm 70 v 7.583 A 4.083 A 1.75 A
Method of work and calculations
• We take three resistors and connect them together in
parallel.
• We take a voltage source and connect it with this circuit.
• We take three devices to measure the current and
connect them with the circuit in order to measure the
current passing through each resistance.
• We turn on the electrical circuit and record the value of
the current
