Question 1

A uniform 8.00-T magnetic field passes perpendicularly through the plane of a wire loop 0.320 m² in area.What flux passes through the loop?

Accepted Answer

B

Question 2

A double loop of wire (making 2 turns)is in the x-y plane centered at the origin.A uniform magnetic field is increasing at a constant rate in the positive z-direction.Viewed from the positive z-axis,in which direction is the induced magnetic field in the loop?

Accepted Answer

According to Faraday's law of induction, an induced EMF is created in a conductor due to a change in magnetic flux. In this case, the magnetic field is increasing in the positive z-direction, which means that the magnetic flux through the double loop is increasing. As the loop is centered at the origin, the induced EMF and current in the loop will produce their own magnetic field that opposes the change in flux. Using the right-hand rule for magnetic fields, the induced magnetic field in the loop will be in the opposite direction of the changing field, which is in the negative z-direction. Therefore, the correct choice is B.

Question 3

A 460-turn solenoid of length 30.0 cm and radius 4.00 cm carries a current of 3.50 A. What is the magnetic field strength inside the coil at its midpoint?
-What is the magnetic flux through a circular cross-sectional area of the solenoid at its midpoint?

Accepted Answer

Using the formula for the magnetic field inside a solenoid:
B = μₒnI
Where μₒ is the permeability of free space and n is the number of turns per unit length (n = N/L).
Plugging in the values, we get:
n = N/L = 460 turns / 0.3 m = 1533.33 turns/m
B = μₒnI = (4π × 10⁻⁷ T·m/A)(1533.33 turns/m)(3.50 A) = 3.39 × 10⁻⁵ T
For the magnetic flux through a circular cross-sectional area, we use:
Φ = BA
Where A is the area of the cross-section and B is the magnetic field at the midpoint.
The area of the cross-section is A = πr² = π(0.04 m)² = 0.00502 m²
Plugging in the values, we get:
Φ = BA = (3.39 × 10⁻⁵ T)(0.00502 m²) = 1.70 × 10⁻⁷ Wb
Therefore, the correct answer is D) 3.39E-5 T/m and 1.70E-7 Wb.

Question 4

A circular loop of wire has its radius reduced in half in time Δt.A uniform magnetic field is at an angle of 60° to the plane of the coil,and the magnetic field doubles its intensity in the same time interval Δt.During this interval,what happens to the flux through the coil?

Accepted Answer

The flux through a coil is given by the formula Φ=BAcosθ, where B is the magnetic field, A is the area of the coil, and θ is the angle between the magnetic field and the plane of the coil. Here, we are given that the magnetic field doubles its intensity, which means B = 2B0, where B0 is the initial magnetic field intensity. We are also given that the radius of the coil is reduced in half, which means the area of the coil is reduced by a factor of 4. Therefore, the new area is A/4 where A is the initial area. Finally, the angle between the magnetic field and the plane of the coil is 60°. 
Putting the given values in the formula, we get:
Φ = (2B0)(A/4)(cos60°)
Φ = (B0A/2)
Since the radius of the coil is reduced in half, the area of the coil is reduced by a factor of 4, therefore the flux through the coil reduces by a factor of 2. 
So, the answer is B) It decreases.

Question 5

A loop of area 0.384 m² is in a uniform 0.0565-T magnetic field.If the flux through the loop is 6.10 × 10-³ T·m²,what angle does the normal to the plane of the loop make with the direction of the magnetic field?

Accepted Answer

The magnetic flux (Φ) is given by Φ = B * A * cos(θ), where B is the magnetic field, A is the area, and θ is the angle between the magnetic field and the normal to the loop. Solving for θ, we get cos(θ) = Φ / (B * A). Substituting the given values, cos(θ) = (6.10 × 10^-3) / (0.0565 * 0.384), which gives θ ≈ 73.7°.

Question 6

A coil is placed in a changing magnetic field and an emf is induced.What happens to the induced emf if the rate of change of magnetic field quadruples?

Accepted Answer

According to Faraday's law, the magnitude of the induced emf is directly proportional to the rate of change of magnetic field. If the rate of change of magnetic field quadruples, then the induced emf will also quadruple. Therefore, the correct choice is C.

Question 7

A coil is placed in a magnetic field and has a flux Φ_B through it.The coil is stressed so that its area reduces to 75% of its original value.If the plane of the coil stays the same and the flux through it remains the same,how must the magnetic field change?

Accepted Answer

The magnetic flux (Φ) through a coil is given by the product of the magnetic field (B), the area of the coil (A), and the cosine of the angle (θ) between the magnetic field and the normal to the area (Φ = B*A*cos(θ)). If the area is reduced to 75% of its original value and the flux remains the same, the magnetic field must increase to compensate for the decrease in area. To maintain the same flux, if the area is reduced to 75% (or 3/4), the magnetic field must increase by a factor of 4/3, which is an increase of 33%.

Question 8

According to Lenz's law the direction of an induced current in a conductor will be that which tends to produce which of the following effects?

Accepted Answer

Lenz's law states that the direction of an induced current in a conductor will be such that it opposes the change that produced it. In other words, the induced current will flow in the direction that creates a magnetic field that opposes the change in the magnetic field that caused the current to be induced. This is also known as the law of conservation of energy, which states that energy cannot be created or destroyed, only transformed from one form to another. Therefore, the induced current must oppose the change in the magnetic field that produced it in order to conserve energy.

Question 9

If the induced current in a wire loop were such that the flux it produces were in the same direction as the change in external flux causing the current,which of the following conservation laws would end up being violated?

Accepted Answer

This scenario would violate the law of conservation of energy, as the induced current producing flux in the same direction as the external change in flux would result in an increase in energy, which violates the principle of conservation of energy.

Question 10

Three loops of wire,one circular,one rectangular,and one square,are made from identical lengths of wire.If the loops are in the same increasing magnetic field perpendicular to the plane of the coils,which loop has the greatest induced emf?

Accepted Answer

The circular loop has the greatest area compared to the rectangular and square loops, which means it will have the greatest magnetic flux through it. According to Faraday's law of electromagnetic induction, the induced emf is proportional to the rate of change of magnetic flux. Therefore, the circular loop will have the greatest induced emf. Since all three loops are made from identical lengths of wire, they have the same resistance, so the circular loop will also have the greatest current flowing through it.

Question 11

The principle or law that says "an induced emf in a circuit loop produces a current whose magnetic field opposes further change of magnetic flux" is credited to:

Accepted Answer

This principle is known as Lenz's law and is named after the physicist Heinrich Lenz. It is a consequence of Faraday's law of induction and states that any change in magnetic flux through a closed loop of wire induces an electromotive force (EMF) that produces a current in the wire, and the direction of the current creates a magnetic field that opposes the change in flux that caused it. This principle is essential in understanding how generators and motors work.

Question 12

A uniform 1.72-T magnetic field passes through the plane of a wire loop 0.46 m² in area.What flux passes through the loop when the direction of the 1.72-T field is at a 38.4° angle to the normal of the loop plane?

Accepted Answer

The magnetic flux is given by Φ = B * A * cos(θ), where B is the magnetic field strength, A is the area, and θ is the angle between the field and the normal to the loop. Substituting the given values: Φ = 1.72 T * 0.46 m² * cos(38.4°) ≈ 0.62 T⋅m².

Question 13

"GFI" stands for:

Accepted Answer

GFI stands for ground fault interrupter, which is a safety device that immediately shuts off power in the event of a ground fault. Choices A, B, and D are not accurate descriptions of what GFI stands for or what it does.

Question 14

The magnetic field inside a circular loop of wire of radius 30 cm increases at a constant rate from 2.0 × 10^-3 T to 3.5 × 10^-3 T in 0.47 s.What is the induced emf in the wire?

Accepted Answer

The answer of The magnetic field inside a circular loop...

Question 15

A 460-turn solenoid of length 30.0 cm and radius 4.00 cm carries a current of 3.50 A. What is the magnetic field strength inside the coil at its midpoint?
-​What is the magnetic field strength inside the coil at its midpoint?

Accepted Answer

The magnetic field strength inside a solenoid can be calculated using the formula: 
B = μ₀NI/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.

Plugging in the given values, we get:

B = (4π×10⁻⁷ Tm/A) × (460 turns) × (3.50 A) ÷ (0.30 m)

Simplifying,

B = 6.74×10⁻³ T

Therefore, the magnetic field strength inside the coil at its midpoint is 6.74×10⁻³ T, which corresponds to answer choice B.

Question 16

A 460-turn solenoid of length 30.0 cm and radius 4.00 cm carries a current of 3.50 A. What is the magnetic field strength inside the coil at its midpoint? -The units T·m²/s are equivalent to:

Accepted Answer

The magnetic field inside a solenoid is given by B = μ_0nI, where μ_0 is the permeability of free space, n is the number of turns per unit length, and I is the current. At the midpoint of the solenoid, n = N/L, where N is the total number of turns and L is the length of the solenoid. Substituting the given values gives: n = N/L = 460/(0.3 m) = 1533.33 m^-1 B = μ_0nI = (4π×10^-7 T·m/A)(1533.33 m^-1)(3.5 A) = 1.72×10^-3 T The units T·m²/s are equivalent to volts (V), which is not a valid choice. The correct unit for magnetic field strength is tesla (T), which has units of N/(A·m) or N·s/(C·m). The other options (W, N/m, and webers) are not relevant to the question.

Question 17

A coil in a magnetic field encloses a flux of 0.196 T·m² when the angle between the normal to the coil and the direction of the magnetic field is 62.0°.What flux would go through the coil if the angle were changed to 38.9°?

Accepted Answer

The magnetic flux through a coil is given by the formula Φ = B*A*cos(θ), where Φ is the magnetic flux, B is the magnetic field strength, A is the area of the coil, and θ is the angle between the magnetic field and the normal to the coil. When the angle changes, the only variable that changes in the formula is θ. Since cos(62.0°) and cos(38.9°) are different, the flux will change proportionally to the cosine of the new angle. Given the initial flux at 62.0°, to find the new flux at 38.9°, we can set up a ratio based on the cosine values of the angles, indicating that the flux will increase as the angle decreases from 62.0° to 38.9°, leading to the correct answer being the one that shows an increase in flux, which is option D.

Question 18

A changing current in one loop of wire can induce a current in another loop of wire even though the wires do not touch.The induced current appears almost instantaneously for loops close together.How can this energy exchange happen?

Accepted Answer

The energy exchange between the two loops of wire is done through an electromagnetic wave. The changing current in the first loop creates a magnetic field that induces an electric field in the second loop, which then results in the current being induced in the second loop. This process occurs through the propagation of electromagnetic waves, which travel at the speed of light and allow for almost instantaneous energy transfer between the two loops.

Question 19

A sensitive ammeter is connected to a wire loop and placed within the magnetic field of a strong horseshoe magnet.The ammeter shows a deflection when:

Accepted Answer

When the wire is moved perpendicularly to the magnetic field, a current is induced in the wire according to Faraday's law of induction. This current is what causes the deflection in the ammeter. Moving parallel to the field (A and D) does not induce a current, and no motion (C) means there is no change in the magnetic field to induce a current.

Question 20

The magnetic field inside a circular loop of wire of radius 30 cm increases at a constant rate from 2.0 × 10^-3 T to 3.5 × 10^-3 T in 0.47 s.If the resistance of the loop is 0.31 Ω,what is the current in the loop?

Accepted Answer

The answer of The magnetic field inside a circular loop...

Quiz 20: Induced Voltages and Inductance

A uniform 8.00-T magnetic field passes perpendicularly through the plane of a wire loop 0.320 m² in area.What flux passes through the loop?

A double loop of wire (making 2 turns) is in the x-y plane centered at the origin.A uniform magnetic field is increasing at a constant rate in the positive z-direction.Viewed from the positive z-axis,in which direction is the induced magnetic field in the loop?

A 460-turn solenoid of length 30.0 cm and radius 4.00 cm carries a current of 3.50 A. What is the magnetic field strength inside the coil at its midpoint? -What is the magnetic flux through a circular cross-sectional area of the solenoid at its midpoint?

A circular loop of wire has its radius reduced in half in time Δt.A uniform magnetic field is at an angle of 60° to the plane of the coil,and the magnetic field doubles its intensity in the same time interval Δt.During this interval,what happens to the flux through the coil?

A loop of area 0.384 m² is in a uniform 0.0565-T magnetic field.If the flux through the loop is 6.10 × 10-³ T·m²,what angle does the normal to the plane of the loop make with the direction of the magnetic field?

A coil is placed in a changing magnetic field and an emf is induced.What happens to the induced emf if the rate of change of magnetic field quadruples?

A coil is placed in a magnetic field and has a flux Φ_B through it.The coil is stressed so that its area reduces to 75% of its original value.If the plane of the coil stays the same and the flux through it remains the same,how must the magnetic field change?

According to Lenz's law the direction of an induced current in a conductor will be that which tends to produce which of the following effects?

If the induced current in a wire loop were such that the flux it produces were in the same direction as the change in external flux causing the current,which of the following conservation laws would end up being violated?

Three loops of wire,one circular,one rectangular,and one square,are made from identical lengths of wire.If the loops are in the same increasing magnetic field perpendicular to the plane of the coils,which loop has the greatest induced emf?

The principle or law that says "an induced emf in a circuit loop produces a current whose magnetic field opposes further change of magnetic flux" is credited to:

A uniform 1.72-T magnetic field passes through the plane of a wire loop 0.46 m² in area.What flux passes through the loop when the direction of the 1.72-T field is at a 38.4° angle to the normal of the loop plane?

"GFI" stands for:

The magnetic field inside a circular loop of wire of radius 30 cm increases at a constant rate from 2.0 × 10^-3 T to 3.5 × 10^-3 T in 0.47 s.What is the induced emf in the wire?

A 460-turn solenoid of length 30.0 cm and radius 4.00 cm carries a current of 3.50 A. What is the magnetic field strength inside the coil at its midpoint? -What is the magnetic field strength inside the coil at its midpoint?

A 460-turn solenoid of length 30.0 cm and radius 4.00 cm carries a current of 3.50 A. What is the magnetic field strength inside the coil at its midpoint? -The units T·m²/s are equivalent to:

A coil in a magnetic field encloses a flux of 0.196 T·m² when the angle between the normal to the coil and the direction of the magnetic field is 62.0°.What flux would go through the coil if the angle were changed to 38.9°?

A changing current in one loop of wire can induce a current in another loop of wire even though the wires do not touch.The induced current appears almost instantaneously for loops close together.How can this energy exchange happen?

A sensitive ammeter is connected to a wire loop and placed within the magnetic field of a strong horseshoe magnet.The ammeter shows a deflection when:

The magnetic field inside a circular loop of wire of radius 30 cm increases at a constant rate from 2.0 × 10^-3 T to 3.5 × 10^-3 T in 0.47 s.If the resistance of the loop is 0.31 Ω,what is the current in the loop?

Quiz 20: Induced Voltages and Inductance

A uniform 8.00-T magnetic field passes perpendicularly through the plane of a wire loop 0.320 m2 in area.What flux passes through the loop?

A double loop of wire (making 2 turns) is in the x-y plane centered at the origin.A uniform magnetic field is increasing at a constant rate in the positive z-direction.Viewed from the positive z-axis,in which direction is the induced magnetic field in the loop?

A 460-turn solenoid of length 30.0 cm and radius 4.00 cm carries a current of 3.50 A. What is the magnetic field strength inside the coil at its midpoint? -What is the magnetic flux through a circular cross-sectional area of the solenoid at its midpoint?

A circular loop of wire has its radius reduced in half in time Δt.A uniform magnetic field is at an angle of 60° to the plane of the coil,and the magnetic field doubles its intensity in the same time interval Δt.During this interval,what happens to the flux through the coil?

A loop of area 0.384 m2 is in a uniform 0.0565-T magnetic field.If the flux through the loop is 6.10 × 10-3 T·m2,what angle does the normal to the plane of the loop make with the direction of the magnetic field?

A coil is placed in a changing magnetic field and an emf is induced.What happens to the induced emf if the rate of change of magnetic field quadruples?

A coil is placed in a magnetic field and has a flux ΦB through it.The coil is stressed so that its area reduces to 75% of its original value.If the plane of the coil stays the same and the flux through it remains the same,how must the magnetic field change?

According to Lenz's law the direction of an induced current in a conductor will be that which tends to produce which of the following effects?

If the induced current in a wire loop were such that the flux it produces were in the same direction as the change in external flux causing the current,which of the following conservation laws would end up being violated?

Three loops of wire,one circular,one rectangular,and one square,are made from identical lengths of wire.If the loops are in the same increasing magnetic field perpendicular to the plane of the coils,which loop has the greatest induced emf?

The principle or law that says "an induced emf in a circuit loop produces a current whose magnetic field opposes further change of magnetic flux" is credited to:

A uniform 1.72-T magnetic field passes through the plane of a wire loop 0.46 m2 in area.What flux passes through the loop when the direction of the 1.72-T field is at a 38.4° angle to the normal of the loop plane?

"GFI" stands for:

The magnetic field inside a circular loop of wire of radius 30 cm increases at a constant rate from 2.0 × 10-3 T to 3.5 × 10-3 T in 0.47 s.What is the induced emf in the wire?

A 460-turn solenoid of length 30.0 cm and radius 4.00 cm carries a current of 3.50 A. What is the magnetic field strength inside the coil at its midpoint? -​What is the magnetic field strength inside the coil at its midpoint?

A 460-turn solenoid of length 30.0 cm and radius 4.00 cm carries a current of 3.50 A. What is the magnetic field strength inside the coil at its midpoint? -The units T·m2/s are equivalent to:

A coil in a magnetic field encloses a flux of 0.196 T·m2 when the angle between the normal to the coil and the direction of the magnetic field is 62.0°.What flux would go through the coil if the angle were changed to 38.9°?

A changing current in one loop of wire can induce a current in another loop of wire even though the wires do not touch.The induced current appears almost instantaneously for loops close together.How can this energy exchange happen?

A sensitive ammeter is connected to a wire loop and placed within the magnetic field of a strong horseshoe magnet.The ammeter shows a deflection when:

The magnetic field inside a circular loop of wire of radius 30 cm increases at a constant rate from 2.0 × 10-3 T to 3.5 × 10-3 T in 0.47 s.If the resistance of the loop is 0.31 Ω,what is the current in the loop?

A uniform 8.00-T magnetic field passes perpendicularly through the plane of a wire loop 0.320 m² in area.What flux passes through the loop?

A loop of area 0.384 m² is in a uniform 0.0565-T magnetic field.If the flux through the loop is 6.10 × 10-³ T·m²,what angle does the normal to the plane of the loop make with the direction of the magnetic field?

A coil is placed in a magnetic field and has a flux Φ_B through it.The coil is stressed so that its area reduces to 75% of its original value.If the plane of the coil stays the same and the flux through it remains the same,how must the magnetic field change?

A uniform 1.72-T magnetic field passes through the plane of a wire loop 0.46 m² in area.What flux passes through the loop when the direction of the 1.72-T field is at a 38.4° angle to the normal of the loop plane?

The magnetic field inside a circular loop of wire of radius 30 cm increases at a constant rate from 2.0 × 10^-3 T to 3.5 × 10^-3 T in 0.47 s.What is the induced emf in the wire?

A 460-turn solenoid of length 30.0 cm and radius 4.00 cm carries a current of 3.50 A. What is the magnetic field strength inside the coil at its midpoint? -What is the magnetic field strength inside the coil at its midpoint?

A 460-turn solenoid of length 30.0 cm and radius 4.00 cm carries a current of 3.50 A. What is the magnetic field strength inside the coil at its midpoint? -The units T·m²/s are equivalent to:

A coil in a magnetic field encloses a flux of 0.196 T·m² when the angle between the normal to the coil and the direction of the magnetic field is 62.0°.What flux would go through the coil if the angle were changed to 38.9°?

The magnetic field inside a circular loop of wire of radius 30 cm increases at a constant rate from 2.0 × 10^-3 T to 3.5 × 10^-3 T in 0.47 s.If the resistance of the loop is 0.31 Ω,what is the current in the loop?