Find net magnetic field due to 'O' .
Answers
Answer:
I will not tell the answer straight but I will tell you how to do it
Explanation:
the loop produce forces that cancel one another. These forces are either zero or are directed along
the axis we take torques around, giving no torque about that axis.
19-7 Magnetic Field from a Long Straight Wire
Let’s now turn to investigating how to
produce a magnetic field. Similar to the way that
electric fields can be set up by charged particles
and act on charged particles, magnetic fields can
be set up by moving charges (or currents) and act
on moving charges. The analog of the point
charge for magnetism is the long straight current-
carrying wire. Figure shows the magnetic
field from a long straight wire. Instead of the field being
proportional to the inverse square of the
distance, as is the electric field from a
point charge, the magnetic field is
inversely proportional to the distance from
the wire. Another difference between the
electric field situation and the magnetic
field situation is that the magnetic field
lines are complete loops.
The magnetic field at a distance r from a long straight wire carrying a current I is
.
The direction of the magnetic field is given by a right-hand rule. In this rule, point the
thumb on your right hand in the direction of the current in the wire. When you curl your fingers,
they curl the same way that the magnetic field curls around the wire. The constant in equation
19.9 is known as the permeability of free space, and has a value of .
In Chapter 8, we analyzed situations involving objects with mass interacting with each
other via the force of gravity. In Chapter 16, we investigated situations involving interacting
charged particles. Let’s investigate analogous magnetic situations involving long straight wires.
EXPLORATION 19.7 – The magnetic force between two parallel wires
A long straight wire (wire 1) carries a current of I1 into the page. A second long straight
wire (wire 2) is located a distance d to the right of wire 1, and carries a current of I2 into the page.
Let’s determine the force per unit length experienced by wire 2 because of wire 1.
Step 1 – Find the magnitude and direction of the magnetic field set up by wire 1 at the location
of wire 2. The magnitude of the field is given by equation 19.9: . To find the
direction of this field at the location of wire 2, recall that the field lines are circular loops centered
on wire 1. Applying the right-hand rule (see the previous page), we find that these field lines go
clockwise. The field at any point is tangent to the field line, so the field at the location of wire 2 is
directed straight down