Ohm S Law
Erica Chan
Sinh Nguyen
Dat Nguyen
Wed 2:00-5:00
02/19/2014
OHM’S LAW
I. Purpose The purpose of this lab is to help understand how voltage, current and resistance are closely related to one another. The outcome from this lab is to be able to differentiate when to use ohmmeter and voltmeter for the individual circuit.
II. Theory Ohm’s Law states that the electric current through a material is directly proportional to the voltage across a piece of material (such as wire) while the resistance is held constant. mathematical equation provides more detailed understanding of the law and is stated as : (or) where, R= resistance in ohms (Ω)
V= potential difference in volt (V)
I= current in ampere (A) The current in a circuit is directly proportional to the electric potential difference and inversely proportional to the total resistance. When only a small current results from a large voltage, there is a high resistance to the moving charge. The greater the voltage is, the greater the current will be. If two variables are given, we can easily find the third variable using Ohm’s law equation.
For example, Given I=4A, V=36V, R=?
Using Ohm’s Law, = = 9Ω From the equation, , we can conclude that 1) if R is constant, an increase in V means an increase in I and vice versa. 2) if V is constant, an increase in I means a decrease in R and vice versa, and 3) if I is constant, an increase in R means an increase in V. From there, we know that .
Since , we are expecting our experimental graph to provide us a straight line.
Current Vs. Voltage
There are two types of resistors in the circuit; they are series and paralllel connections.
Series connection
In series connection, the current flows through each resistor is the same. There is only one path for the current to pass through. The voltage drop is proportional to the resistance of individual resistors.
Rtotal is larger than any of the individual R.
Parallel connection
In parallel connection, the the voltage
Sinh Nguyen
Dat Nguyen
Wed 2:00-5:00
02/19/2014
OHM’S LAW
I. Purpose The purpose of this lab is to help understand how voltage, current and resistance are closely related to one another. The outcome from this lab is to be able to differentiate when to use ohmmeter and voltmeter for the individual circuit.
II. Theory Ohm’s Law states that the electric current through a material is directly proportional to the voltage across a piece of material (such as wire) while the resistance is held constant. mathematical equation provides more detailed understanding of the law and is stated as : (or) where, R= resistance in ohms (Ω)
V= potential difference in volt (V)
I= current in ampere (A) The current in a circuit is directly proportional to the electric potential difference and inversely proportional to the total resistance. When only a small current results from a large voltage, there is a high resistance to the moving charge. The greater the voltage is, the greater the current will be. If two variables are given, we can easily find the third variable using Ohm’s law equation.
For example, Given I=4A, V=36V, R=?
Using Ohm’s Law, = = 9Ω From the equation, , we can conclude that 1) if R is constant, an increase in V means an increase in I and vice versa. 2) if V is constant, an increase in I means a decrease in R and vice versa, and 3) if I is constant, an increase in R means an increase in V. From there, we know that .
Since , we are expecting our experimental graph to provide us a straight line.
Current Vs. Voltage
There are two types of resistors in the circuit; they are series and paralllel connections.
Series connection
In series connection, the current flows through each resistor is the same. There is only one path for the current to pass through. The voltage drop is proportional to the resistance of individual resistors.
Rtotal is larger than any of the individual R.
Parallel connection
In parallel connection, the the voltage