Question 1

Two very long parallel wires in the xy-plane,a distance 2a apart,are parallel to the y-axis and carry equal currents I as shown in the figure.The +z direction points perpendicular to the xy-plane in a right-handed coordinate system.If the left current flows in the +y direction and the right current flows in the -y direction,which one of the graphs shown in the figure below best represents the z component of the net magnetic field,in the xy-plane,as a function of x? (Caution: These graphs are not magnetic field lines.)  
A) 1
B) 2
C) 3
D) 4
E) 5

Accepted Answer

The answer of Two very long parallel wires in the...

Question 2

The figure shows three long,parallel,current-carrying wires.The current directions are indicated for currents I₁ and I₃.The arrow labeled F represents the net magnetic force acting on current I₃.The three currents have equal magnitudes.What is the direction of the current I₂? A) into the picture (in the direction opposite to that of I₁ and I₃) B) horizontal to the right C) vertically upward D) vertically downward E) out of the picture (in the same direction as I₁ and I₃)

Accepted Answer

The answer of The figure shows three long,parallel,current-carrying wires.The current...

Question 3

Consider a solenoid of length L,N windings,and radius b (L is much longer than b).A current I is flowing through the wire.If the radius of the solenoid were doubled (becoming 2b),and all other quantities remained the same,the magnetic field inside the solenoid would
A) remain the same.
B) become twice as strong.
C) become one half as strong.

Accepted Answer

The magnetic field inside a long solenoid is given by the formula B = μ₀(NI/L), where μ₀ is the permeability of free space, N is the number of turns, I is the current, and L is the length of the solenoid. This formula shows that the magnetic field inside a solenoid depends on the number of turns per unit length and the current, but not on the radius of the solenoid. Therefore, doubling the radius while keeping all other factors constant does not change the magnetic field strength inside the solenoid.

Question 4

A wire along the z-axis carries a current of 6.8 A in the +z direction.Find the magnitude and direction of the force exerted on a 6.1-cm long length of the wire by a uniform magnetic field with magnitude 0.36 T in the -x direction.

Accepted Answer

The answer of A wire along the z-axis carries a...

Question 5

Two very long parallel wires are a distance d apart and carry equal currents in opposite directions.The locations where the net magnetic field due to these currents is equal to zero are
A) midway between the wires.
B) a distance d/2 to the left of the left wire and also a distance d/2 to the right of the right wire.
C) a distance d to the left of the left wire and also a distance d to the right of the right wire.
D) a distance d/  to the left of the left wire and also a distance d/
 to the right of the right wire.
E) The net field is not zero anywhere.

Accepted Answer

The answer of Two very long parallel wires are a...

Question 6

A long straight conductor has a constant current flowing to the right.A wire rectangle is situated above the wire,and also has a constant current flowing through it (as shown in the figure).Which of the following statements is true? 
A) The net magnetic force on the wire rectangle is upward, and there is also a net torque on it.
B) The net magnetic force on the wire rectangle is zero, and the net torque on it is zero.
C) The net magnetic force on the wire rectangle is downward, and there is also a net torque on it.
D) The net magnetic force on the wire rectangle is zero, but there is a net torque on it.
E) The net magnetic force on the wire rectangle is downward, and the net torque on it is zero.

Accepted Answer

The answer of A long straight conductor has a constant...

Question 7

A very long thin wire produces a magnetic field of 0.0050 × 10^-4 T at a distance of 3.0 mm from the central axis of the wire.What is the magnitude of the current in the wire? (μ₀ = 4π × 10^-7 T • m/A) A) 7.5 mA B) 1.7 mA C) 3300 mA D) 24,000 mA

Accepted Answer

The answer of A very long thin wire produces a...

Question 8

A point charge Q moves on the x-axis in the positive direction with a speed of 370 m/s.A point P is on the y-axis at y = +80 mm.The magnetic field produced at point P,as the charge moves through the origin,is equal to When the charge is at x = +40 mm,what is the magnitude of the magnetic field at point P? (μ₀ = 4π × 10^-7 T • m/A) A) 0.57 μT B) 0.74 μT C) 0.92 μT D) 1.1 μT E) 1.3 μT

Accepted Answer

The answer of A point charge Q moves on the...

Question 9

Two long parallel wires placed side-by-side on a horizontal table carry identical size currents in opposite directions.The wire on your right carries current toward you,and the wire on your left carries current away from you.From your point of view,the magnetic field at the point exactly midway between the two wires
A) points upward.
B) points downward.
C) points toward you.
D) points away from you.
E) is zero.

Accepted Answer

The answer of Two long parallel wires placed side-by-side on...

Question 10

The figure shows four different sets of insulated wires that cross each other at right angles without actually making electrical contact.The magnitude of the current is the same in all the wires,and the directions of current flow are as indicated.For which (if any)configuration will the magnetic field at the center of the square formed by the wires be equal to zero? 
A) A
B) B
C) C
D) D
E) The field is not equal to zero in any of these cases.

Accepted Answer

The answer of The figure shows four different sets of...

Question 11

A rigid rectangular loop,which measures 0.30 m by 0.40 m,carries a current of 5.5 A,as shown in the figure.A uniform external magnetic field of magnitude 2.9 T in the negative x direction is present.Segment CD is in the xz-plane and forms a 35° angle with the z-axis,as shown.Find the magnitude of the external torque needed to keep the loop in static equilibrium. 
A) 1.1 N • m
B) 0.73 N • m
C) 1.3 N • m
D) 1.4 N • m
E) 1.6 N • m

Accepted Answer

The answer of A rigid rectangular loop,which measures 0.30 m...

Question 12

Consider a solenoid of length L,N windings,and radius b (L is much longer than b).A current I is flowing through the wire.If the length of the solenoid became twice as long (2L),and all other quantities remained the same,the magnetic field inside the solenoid would
A) remain the same.
B) become twice as strong.
C) become one half as strong.

Accepted Answer

The magnetic field inside the solenoid is given by B = μ₀NI/L, where μ₀ is the permeability of free space. If the length of the solenoid is doubled but the number of windings and current remain the same, then the new magnetic field would be B' = μ₀NI/2L. We can see that B' is one-half of the original field B. Therefore, the correct choice is C.

Question 13

Two very long parallel wires in the xy-plane,a distance 2a apart,are parallel to the y-axis and carry equal currents I as shown in the figure.The +z direction points perpendicular to the xy-plane in a right-handed coordinate system.If both currents flow in the +y direction,which one of the graphs shown in the figure below best represents the z component of the net magnetic field,in the xy-plane,as a function of x? (Caution: These graphs are not magnetic field lines.)  
A) 1
B) 2
C) 3
D) 4
E) 5

Accepted Answer

The answer of Two very long parallel wires in the...

Question 14

A ring with a clockwise current (as seen from above the ring)is situated with its center directly above another ring,which has a counter-clockwise current,as shown in the figure.In what direction is the net magnetic force exerted on the top ring? 
A) upward
B) downward
C) to the right
D) to the left
E) The net force is zero.

Accepted Answer

The answer of A ring with a clockwise current (as...

Question 15

At what distance from the central axis of a long straight thin wire carrying a current of 5.0 A is the magnitude of the magnetic field due to the wire equal to the strength of the Earth's magnetic field of about 5.0 × 10^-5 T? (μ₀ = 4π × 10^-7 T • m/A) A) 1.0 cm B) 2.0 cm C) 3.0 cm D) 4.0 cm E) 5.0 cm

Accepted Answer

We can use the formula for the magnetic field due to a long straight wire, given by:

B = μ₀I/2πr

Where B is the magnetic field, μ₀ is the vacuum permeability (given as μ₀ = 4π × 10^-7 T · m/A), I is the current, and r is the distance from the wire.

We want to find the distance at which the magnetic field B is equal to the strength of the Earth's magnetic field, given as B = 5.0 × 10^-5 T.

Setting these two expressions equal, we get:

5.0 × 10^-5 T = μ₀I/2πr

Solving for r, we get:

r = μ₀I/2πB

Plugging in the given values, we get:

r = (4π × 10^-7 T · m/A)(5.0 A)/(2π)(5.0 × 10^-5 T) ≈ 2.0 cm

Therefore, the answer is B) 2.0 cm.

Question 16

A wire segment 1.2 m long carries a current I = 3.5 A,and is oriented as shown in the figure.The +x-axis points directly into the page.A uniform magnetic field of magnitude 0.50 T pointing toward the -x direction is present as shown.What is the magnetic force vector on the wire segment? 
A) (+1.1  - 1.8
 ) N
B) (-1.1  + 1.8
 ) N
C) (-1.1  - 1.8
 ) N
D) (+1.8  - 1.1
 ) N
E) (-1.8  + 1.1
 ) N

Accepted Answer

The answer of A wire segment 1.2 m long carries...

Question 17

The figure shows two long wires carrying equal currents I₁ and I₂ flowing in opposite directions.Which of the arrows labeled A through D correctly represents the direction of the magnetic field due to the wires at a point located at an equal distance d from each wire? A) A B) B C) C D) D E) The magnetic field is zero at that point.

Accepted Answer

The answer of The figure shows two long wires carrying...

Question 18

The figure shows three long,parallel current-carrying wires.The magnitudes of the currents are equal and their directions are indicated in the figure.Which of the arrows drawn near the wire carrying current 1 correctly indicates the direction of the magnetic force acting on that wire? 
A) A
B) B
C) C
D) D
E) The magnetic force on current 1 is equal to zero.

Accepted Answer

The answer of The figure shows three long,parallel current-carrying wires.The...

Question 19

A point charge Q moves on the x-axis in the positive direction with a speed of 280 m/s.A point P is on the y-axis at y = +70 mm.The magnetic field produced at the point P,as the charge moves through the origin,is equal to What is the charge Q? (μ₀ = 4π × 10^-7 T • m/A) A) -53 μC B) +53 μC C) -39 μC D) +39 μC E) +26 μC

Accepted Answer

The answer of A point charge Q moves on the...

Question 20

A negatively charged particle is moving to the right,directly above a wire having a current flowing to the right,as shown in the figure.In which direction is the magnetic force exerted on the particle? 
A) into the page
B) out of the page
C) downward
D) upward
E) The magnetic force is zero since the velocity is parallel to the current.

Accepted Answer

According to the right-hand rule, the direction of the magnetic force on a negatively charged particle moving to the right above a current-carrying wire flowing to the right is upward.

Quiz 1: A: Foundations

The figure shows three long,parallel,current-carrying wires.The current directions are indicated for currents I₁ and I₃.The arrow labeled F represents the net magnetic force acting on current I₃.The three currents have equal magnitudes.What is the direction of the current I₂?

Consider a solenoid of length L,N windings,and radius b (L is much longer than b) .A current I is flowing through the wire.If the radius of the solenoid were doubled (becoming 2b) ,and all other quantities remained the same,the magnetic field inside the solenoid would

A wire along the z-axis carries a current of 6.8 A in the +z direction.Find the magnitude and direction of the force exerted on a 6.1-cm long length of the wire by a uniform magnetic field with magnitude 0.36 T in the -x direction.

Two very long parallel wires are a distance d apart and carry equal currents in opposite directions.The locations where the net magnetic field due to these currents is equal to zero are

A long straight conductor has a constant current flowing to the right.A wire rectangle is situated above the wire,and also has a constant current flowing through it (as shown in the figure) .Which of the following statements is true?

A very long thin wire produces a magnetic field of 0.0050 × 10^-4 T at a distance of 3.0 mm from the central axis of the wire.What is the magnitude of the current in the wire? (μ₀ = 4π × 10^-7 T • m/A)

Consider a solenoid of length L,N windings,and radius b (L is much longer than b) .A current I is flowing through the wire.If the length of the solenoid became twice as long (2L) ,and all other quantities remained the same,the magnetic field inside the solenoid would

A ring with a clockwise current (as seen from above the ring) is situated with its center directly above another ring,which has a counter-clockwise current,as shown in the figure.In what direction is the net magnetic force exerted on the top ring?

At what distance from the central axis of a long straight thin wire carrying a current of 5.0 A is the magnitude of the magnetic field due to the wire equal to the strength of the Earth's magnetic field of about 5.0 × 10^-5 T? (μ₀ = 4π × 10^-7 T • m/A)

A wire segment 1.2 m long carries a current I = 3.5 A,and is oriented as shown in the figure.The +x-axis points directly into the page.A uniform magnetic field of magnitude 0.50 T pointing toward the -x direction is present as shown.What is the magnetic force vector on the wire segment?

The figure shows two long wires carrying equal currents I₁ and I₂ flowing in opposite directions.Which of the arrows labeled A through D correctly represents the direction of the magnetic field due to the wires at a point located at an equal distance d from each wire?

The figure shows three long,parallel current-carrying wires.The magnitudes of the currents are equal and their directions are indicated in the figure.Which of the arrows drawn near the wire carrying current 1 correctly indicates the direction of the magnetic force acting on that wire?

A point charge Q moves on the x-axis in the positive direction with a speed of 280 m/s.A point P is on the y-axis at y = +70 mm.The magnetic field produced at the point P,as the charge moves through the origin,is equal to What is the charge Q? (μ₀ = 4π × 10^-7 T • m/A)

A negatively charged particle is moving to the right,directly above a wire having a current flowing to the right,as shown in the figure.In which direction is the magnetic force exerted on the particle?

Quiz 1: A: Foundations

The figure shows three long,parallel,current-carrying wires.The current directions are indicated for currents I1 and I3.The arrow labeled F represents the net magnetic force acting on current I3.The three currents have equal magnitudes.What is the direction of the current I2?

Consider a solenoid of length L,N windings,and radius b (L is much longer than b) .A current I is flowing through the wire.If the radius of the solenoid were doubled (becoming 2b) ,and all other quantities remained the same,the magnetic field inside the solenoid would

A wire along the z-axis carries a current of 6.8 A in the +z direction.Find the magnitude and direction of the force exerted on a 6.1-cm long length of the wire by a uniform magnetic field with magnitude 0.36 T in the -x direction.

Two very long parallel wires are a distance d apart and carry equal currents in opposite directions.The locations where the net magnetic field due to these currents is equal to zero are

A long straight conductor has a constant current flowing to the right.A wire rectangle is situated above the wire,and also has a constant current flowing through it (as shown in the figure) .Which of the following statements is true?

A very long thin wire produces a magnetic field of 0.0050 × 10-4 T at a distance of 3.0 mm from the central axis of the wire.What is the magnitude of the current in the wire? (μ0 = 4π × 10-7 T • m/A)

Consider a solenoid of length L,N windings,and radius b (L is much longer than b) .A current I is flowing through the wire.If the length of the solenoid became twice as long (2L) ,and all other quantities remained the same,the magnetic field inside the solenoid would

A ring with a clockwise current (as seen from above the ring) is situated with its center directly above another ring,which has a counter-clockwise current,as shown in the figure.In what direction is the net magnetic force exerted on the top ring?

At what distance from the central axis of a long straight thin wire carrying a current of 5.0 A is the magnitude of the magnetic field due to the wire equal to the strength of the Earth's magnetic field of about 5.0 × 10-5 T? (μ0 = 4π × 10-7 T • m/A)

A wire segment 1.2 m long carries a current I = 3.5 A,and is oriented as shown in the figure.The +x-axis points directly into the page.A uniform magnetic field of magnitude 0.50 T pointing toward the -x direction is present as shown.What is the magnetic force vector on the wire segment?

The figure shows two long wires carrying equal currents I1 and I2 flowing in opposite directions.Which of the arrows labeled A through D correctly represents the direction of the magnetic field due to the wires at a point located at an equal distance d from each wire?

The figure shows three long,parallel current-carrying wires.The magnitudes of the currents are equal and their directions are indicated in the figure.Which of the arrows drawn near the wire carrying current 1 correctly indicates the direction of the magnetic force acting on that wire?

A point charge Q moves on the x-axis in the positive direction with a speed of 280 m/s.A point P is on the y-axis at y = +70 mm.The magnetic field produced at the point P,as the charge moves through the origin,is equal to What is the charge Q? (μ0 = 4π × 10-7 T • m/A)

A negatively charged particle is moving to the right,directly above a wire having a current flowing to the right,as shown in the figure.In which direction is the magnetic force exerted on the particle?

The figure shows three long,parallel,current-carrying wires.The current directions are indicated for currents I₁ and I₃.The arrow labeled F represents the net magnetic force acting on current I₃.The three currents have equal magnitudes.What is the direction of the current I₂?

A very long thin wire produces a magnetic field of 0.0050 × 10^-4 T at a distance of 3.0 mm from the central axis of the wire.What is the magnitude of the current in the wire? (μ₀ = 4π × 10^-7 T • m/A)

At what distance from the central axis of a long straight thin wire carrying a current of 5.0 A is the magnitude of the magnetic field due to the wire equal to the strength of the Earth's magnetic field of about 5.0 × 10^-5 T? (μ₀ = 4π × 10^-7 T • m/A)

The figure shows two long wires carrying equal currents I₁ and I₂ flowing in opposite directions.Which of the arrows labeled A through D correctly represents the direction of the magnetic field due to the wires at a point located at an equal distance d from each wire?

A point charge Q moves on the x-axis in the positive direction with a speed of 280 m/s.A point P is on the y-axis at y = +70 mm.The magnetic field produced at the point P,as the charge moves through the origin,is equal to What is the charge Q? (μ₀ = 4π × 10^-7 T • m/A)