Clicker Question
The circuit shown is constructed on a horizontal table
and a compass is placed on top of the circuit as shown.
Which way should the battery be placed in the circuit
so when the switch is closed, the compass needle
deflects counterclockwise?
A) Orientation A
B) Orientation B
Clicker Question
The circuit shown is constructed on a horizontal table
and a compass is placed on top of the circuit as shown.
Which way should the battery be placed in the circuit
so when the switch is closed, the compass needle
deflects counterclockwise?
A) Orientation A
B) Orientation B
Clicker Question
The wire shown here is
infinitely long and has a 90°
bend. If current flows in the
wire as shown, what is the
direction of the magnetic
field at P due to the
current?
A. to the right
B. to the left
C. out of the plane of the figure
D. into the plane of the figure
E. none of these
Clicker Question
The wire shown here is
infinitely long and has a 90°
bend. If current flows in the
wire as shown, what is the
direction of the magnetic
field at P due to the
current?
A. to the right
B. to the left
C. out of the plane of the figure
D. into the plane of the figure
E. none of these
Clicker Question
The wires shown are
infinitely long and each has
a 90° bend. If current flows
as shown, what is the
magnitude of the magnetic
field at P due to the
current?
A) 0
B) µoI/(2πa)
C) µoI/(πa)
D) 2µoI/(πa)
E) µoI/(4πa)
Clicker Question
The wires shown are
infinitely long and each has
a 90° bend. If current flows
as shown, what is the
magnitude of the magnetic
field at P due to the
current?
A) 0
B) µoI/(2πa)
C) µoI/(πa)
D) 2µoI/(πa)
E) µoI/(4πa)
Clicker Question
If current flows as shown, what is the magnitude of the
magnetic field at P due to the current?
A) 0
B) µoI/(2πa)
C) µoI/(2a)
D) 2µoI/(πa)
E) µoI/(4πa)
Clicker Question
If current flows as shown, what is the magnitude of the
magnetic field at P due to the current?
A) 0
B) µoI/(2πa)
C) µoI/(2a)
D) 2µoI/(πa)
E) µoI/(4πa)
Clicker Question
Point P is at a perpendicular distance x from each wire
carry current I in the directions indicated. What is the
magnetic field B at point P?
I
A) 0
B) µoI/(2πx)
C) µoI/(πx)
D) not sure
E) all of the above
x
I
x
P
Clicker Question
Point P is at a perpendicular distance x from each wire
carry current I in the directions indicated. What is the
magnetic field B at point P?
I
A) 0
B) µoI/(2πx)
C) µoI/(πx)
D) not sure
E) all of the above
x
I
x
P
Clicker Question
A wire consists of two straight
sections with a semicircular
section between them. If current
flows in the wire as shown, what
is the direction of the magnetic
field at P due to the current?
A. to the right
B. to the left
C. out of the plane of the figure
D. into the plane of the figure
E. misleading question — the magnetic field at P is zero
Clicker Question
A wire consists of two straight
sections with a semicircular
section between them. If current
flows in the wire as shown, what
is the direction of the magnetic
field at P due to the current?
A. to the right
B. to the left
C. out of the plane of the figure
D. into the plane of the figure
E. misleading question — the magnetic field at P is zero
Clicker Question
What is the
magnitude and
direction of the
magnetic field at
point P?
A) 0
B) µoI/(2R) out of the page
C) µoI/(πR) into the page
D) µoI/(R) out of the page
E) µoI/(2R) into the page
Clicker Question
What is the
magnitude and
direction of the
magnetic field at
point P?
A) 0
B) µoI/(2R) out of the page
C) µoI/(πR) into the page
D) µoI/(R) out of the page
E) µoI/(2R) into the page
Clicker Question
What is the magnitude of the
magnetic field at point P?
A) µoI/(2R)
B) µoI/(2R)
C) µoI/(4πR)
D) µoI/(R)
E) µoI/(4R)
Clicker Question
What is the magnitude of the
magnetic field at point P?
A) µoI/(2R)
B) µoI/(2R)
C) µoI/(4πR)
D) µoI/(R)
E) µoI/(4R)
Clicker Question
The figure shows, in cross section,
three conductors that carry
currents perpendicular to the plane
of the figure.
If the currents I1, I2, and I3 all have the
same magnitude, for which path(s)
is the line integral of the magnetic
field equal to zero?
A. path a only
B. paths a and c
C. paths b and d
D. paths a, b, c, and d
E. The answer depends on whether the integral goes
clockwise or counterclockwise around the path.
Clicker Question
The figure shows, in cross section,
three conductors that carry
currents perpendicular to the plane
of the figure.
If the currents I1, I2, and I3 all have the
same magnitude, for which path(s)
is the line integral of the magnetic
field equal to zero?
A. path a only
B. paths a and c
C. paths b and d
D. paths a, b, c, and d
E. The answer depends on whether the integral goes
clockwise or counterclockwise around the path.
Clicker Question
Recall that

 
E  dA = qenc /0
What is the total flux of the magnetic field through any
closed surface?
 
 B  dA = ?
A) zero
B) Ienc times a positive constant
C) -Ienc times a positive constant
Clicker Question
Recall that

 
E  dA = qenc /0
What is the total flux of the magnetic field through any
closed surface?
 
 B  dA = ?
A) zero
B) Ienc times a positive constant
C) -Ienc times a positive constant