PHYS 2240Section 516
Performed: 03/29/2016
E
XPERIMENT
7
M
AGNETIC
F
IELD
IN
A
C
URRENT
C
ARRYING
C
OIL
Anagha Krishnan
PHYS 2240Section 516
Lab 7 Report
Anagha Krishnan
L
AB
R
EPORT
7: M
AGNETIC
F
IELD
IN
A
C
URRENT

C
ARRYING
C
OIL
I
NTRODUCTION
In this experiment, the currentcarrying coil’s axial and radial magnetic fields are
plotted versus position as a Magnetic Field Sensor passes through the coil. The magnetic
fields are plotted experimentally for a short solenoid by using the Electronics Laboratory
and are approximated by using the equation for the magnetic field of a single coil and the
equation for the magnetic field of a long solenoid.
T
HEORY
S
INGLE
C
OIL
A resistor is a device that resists the passage of an electric current, and in general, it
obeys Ohm’s Law. Resistors can be connected in one of three ways: in series (see Circuit
Diagram 1), in parallel (see Circuit Diagram 2) or in a series parallel combination (see
Circuit Diagrams 3 and 4).
An equivalent resistor is a single resistor that can replace a
complicated series parallel circuit to produce the same resistance. It thus produces the
same current as the original series parallel circuit as long as we apply the same total voltage
to both systems.
For a series circuit, we can add the individual resistances to calculate the equivalent
resistance, as shown in Equation 1. For a parallel circuit, we instead add the reciprocals of
the individual resistances to calculate the reciprocal of the equivalent resistance (Equation
2), which we can then invert to find the true equivalent resistance. We can combine and
manipulate these two equations to find the equivalent resistance for increasingly
complicated series parallel circuits.
R
eq
=
R
1
+
R
2
(
Equation
1
−
Equivalent Resistance of aSeriesCircuit
)
In this equation, R
eq
represents the equivalent resistance, and R
1
and R
2
represent the individual resistances of the components
of the system
1
R
eq
=
1
R
1
+
1
R
2
(
Equation
2
−
Equivalent Resistanceof a
∥
Circuit
)
2
PHYS 2240Section 516
Lab 7 Report
Anagha Krishnan
In this equation, R
eq
again represents the equivalent resistance, and R
1
and R
2
represent the individual resistances of the
components of the system
L
ONG
S
OLENOID
S
HORT
S
OLENOID
Ohm’s Law is an equation that designates the relationship between voltage (also
known as the electric potential difference), current, and resistance. Ohm’s Law states that
the electric potential difference between two points (V) is equivalent to the product of the
current between the two points (I) and the total resistance of the system (R). Equation 3
shows this relationship.
V
=
IR
(
Equation
3
−
Ohm
'
s Law
)
In this equation, V is the voltage (or the electric potential difference), I is the current, and R is the resistance.