Question 1

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 least induced emf?

Accepted Answer

B

Question 2

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

Accepted Answer

A

Question 3

A uniform 1.5-T magnetic field passes perpendicularly through the plane of a wire loop 0.30 m² in area. What flux passes through the loop?

Accepted Answer

The magnetic flux (Φ) through the loop is given by the formula Φ = B * A, where B is the magnetic field strength (1.5 T) and A is the area of the loop (0.30 m²). Thus, Φ = 1.5 T * 0.30 m² = 0.45 T·m².

Question 4

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

Accepted Answer

The answer of A circular loop of wire has its...

Question 5

The magnetic field inside a circular loop of wire of radius 30 cm increases at a constant rate from  to  in 0.47 s. If the resistance of the loop is 0.31$\Omega$, what is the current in the loop?

Accepted Answer

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

Question 6

A 0.200-m wire is moved parallel to a 0.500-T magnetic field at a speed of 6.00 m/s. What emf is induced across the ends of the wire?

Accepted Answer

The answer of A 0.200-m wire is moved parallel to...

Question 7

Electricity may be generated by rotating a loop of wire between the poles of a magnet. The induced current is least when:

Accepted Answer

The answer of Electricity may be generated by rotating a...

Question 8

A straight wire of length  is oriented east-west and is in a magnetic field B pointing north. The wire is moving upward at a constant speed v. Which end of the rod is positively charged?

Accepted Answer

The answer of A straight wire of length  is...

Question 9

A metal rod is falling toward the surface of the Earth near the equator. As it falls, one end of the rod becomes positively charged due to the motional emf of the rod through the Earth's magnetic field. The rod is oriented so that:

Accepted Answer

As the rod falls through the Earth's magnetic field, the motion of the rod induces an emf due to the Lorentz force. Near the equator, the Earth's magnetic field is approximately horizontal and points from south to north. Using the right-hand rule, with the velocity of the rod downward and the magnetic field pointing north, the induced current will cause the positive charge to accumulate on the east end of the rod.

Question 10

A straight wire of length  is oriented east-west and is in a magnetic field B pointing north. The wire is moving downward at a constant speed v. If the resistance of the rod is R, what is the current through the rod?

Accepted Answer

The answer of A straight wire of length  is...

Question 11

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 negative z direction. In which direction is the induced magnetic field in the loop?

Accepted Answer

According to Lenz's Law, the induced magnetic field will oppose the change in the external magnetic field. Since the external magnetic field is increasing in the negative z direction, the induced magnetic field will be in the positive z direction to oppose this change.

Question 12

A coil is placed in a magnetic field and has a flux $\varPsi$_B through it. The coil is stressed so that its area reduces to 60% 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 field must increase by 67% because the area of the coil is reduced to 60% of its original value, so the magnetic field must increase to compensate for the reduced area to keep the flux constant. The increase needed is calculated as (1/0.6) - 1 = 0.67 or 67%.

Question 13

An airplane with a wingspan of 60.0 m flies parallel to the Earth's surface at a point where the downward component of the Earth's magnetic field is 0.400 * l0^-⁴ T. If the induced potential between wingtips is 0.600 V, what is the plane's speed?

Accepted Answer

The answer of An airplane with a wingspan of 60.0...

Question 14

Magnetism had been a known phenomenon for some time before its relation to electric currents was found. That a current in a wire produces a magnetic field was discovered by:

Accepted Answer

Hans Christian Ørsted discovered that an electric current in a wire produces a magnetic field, which was a pivotal finding in the study of electromagnetism.

Question 15

A loop of area 0.250 m² is in a uniform 0.0200-T magnetic field. If the flux through the loop is 3.21 * 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 answer of A loop of area 0.250 m² is...

Question 16

A large jetliner with a wingspan of 40 m flies horizontally and due north at a speed of 300 m/s in a region where the magnetic field of the earth is 51 µT directed 24.1° below the horizontal. What is the magnitude of the induced emf between the ends of the wing?

Accepted Answer

The answer of A large jetliner with a wingspan of...

Question 17

A uniform 4.5-T magnetic field passes through the plane of a wire loop 0.20 m²in area. What flux passes through the loop when the direction of the 4.5-T field is at a 30° angle to the normal of the loop plane?

Accepted Answer

The magnetic flux is given by the formula 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 = 4.5 T * 0.20 m² * cos(30°) = 0.78 T·m².

Question 18

The units T·m²/s are equivalent to:

Accepted Answer

The answer of The units T·m²/s are equivalent to: ...

Question 19

A coil in a magnetic field encloses a flux of 0.256 T·m² when the angle between the normal to the coil and the direction of the magnetic field is 70.0°. What flux would go through the coil if the angle were changed to 30.0°?

Accepted Answer

We can use the formula for flux through a coil in a magnetic field: Φ = B*A*cos(θ) where Φ is the flux, B is the magnetic field, A is the area enclosed by the coil, and θ is the angle between the normal to the coil and the direction of the magnetic field. We can rearrange the formula to solve for the new flux when the angle is changed to 30.0°: Φ' = B*A*cos(30.0°) = (0.256 T) * (m^2) * cos(30.0°) = 0.648 T·m² Therefore, the answer is A.

Question 20

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

The ammeter shows a deflection when there is a change in magnetic flux through the loop, which occurs when the wire is moved perpendicularly to the magnetic field lines, inducing an electromotive force (EMF) and current in the wire.

Quiz 21: Magnetic Induction

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 least induced emf?

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

A uniform 1.5-T magnetic field passes perpendicularly through the plane of a wire loop 0.30 m² in area. What flux passes through the loop?

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

A 0.200-m wire is moved parallel to a 0.500-T magnetic field at a speed of 6.00 m/s. What emf is induced across the ends of the wire?

Electricity may be generated by rotating a loop of wire between the poles of a magnet. The induced current is least when:

A straight wire of length is oriented east-west and is in a magnetic field B pointing north. The wire is moving upward at a constant speed v. Which end of the rod is positively charged?

A metal rod is falling toward the surface of the Earth near the equator. As it falls, one end of the rod becomes positively charged due to the motional emf of the rod through the Earth's magnetic field. The rod is oriented so that:

A straight wire of length is oriented east-west and is in a magnetic field B pointing north. The wire is moving downward at a constant speed v. If the resistance of the rod is R, what is the current through the rod?

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 negative z direction. In which direction is the induced magnetic field in the loop?

A coil is placed in a magnetic field and has a flux $\varPsi$ _B through it. The coil is stressed so that its area reduces to 60% 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?

An airplane with a wingspan of 60.0 m flies parallel to the Earth's surface at a point where the downward component of the Earth's magnetic field is 0.400 * l0^-⁴ T. If the induced potential between wingtips is 0.600 V, what is the plane's speed?

Magnetism had been a known phenomenon for some time before its relation to electric currents was found. That a current in a wire produces a magnetic field was discovered by:

A loop of area 0.250 m² is in a uniform 0.0200-T magnetic field. If the flux through the loop is 3.21 * 10^-3 T·m², what angle does the normal to the plane of the loop make with the direction of the magnetic field?

A large jetliner with a wingspan of 40 m flies horizontally and due north at a speed of 300 m/s in a region where the magnetic field of the earth is 51 µT directed 24.1° below the horizontal. What is the magnitude of the induced emf between the ends of the wing?

A uniform 4.5-T magnetic field passes through the plane of a wire loop 0.20 m²in area. What flux passes through the loop when the direction of the 4.5-T field is at a 30° angle to the normal of the loop plane?

The units T·m²/s are equivalent to:

A coil in a magnetic field encloses a flux of 0.256 T·m² when the angle between the normal to the coil and the direction of the magnetic field is 70.0°. What flux would go through the coil if the angle were changed to 30.0°?

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:

Quiz 21: Magnetic Induction

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 least induced emf?

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

A uniform 1.5-T magnetic field passes perpendicularly through the plane of a wire loop 0.30 m2 in area. What flux passes through the loop?

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

The magnetic field inside a circular loop of wire of radius 30 cm increases at a constant rate from to in 0.47 s. If the resistance of the loop is 0.31 Ω\OmegaΩ , what is the current in the loop?

A 0.200-m wire is moved parallel to a 0.500-T magnetic field at a speed of 6.00 m/s. What emf is induced across the ends of the wire?

Electricity may be generated by rotating a loop of wire between the poles of a magnet. The induced current is least when:

A straight wire of length is oriented east-west and is in a magnetic field B pointing north. The wire is moving upward at a constant speed v. Which end of the rod is positively charged?

A metal rod is falling toward the surface of the Earth near the equator. As it falls, one end of the rod becomes positively charged due to the motional emf of the rod through the Earth's magnetic field. The rod is oriented so that:

A straight wire of length is oriented east-west and is in a magnetic field B pointing north. The wire is moving downward at a constant speed v. If the resistance of the rod is R, what is the current through the rod?

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 negative z direction. In which direction is the induced magnetic field in the loop?

A coil is placed in a magnetic field and has a flux Ψ\varPsiΨ B through it. The coil is stressed so that its area reduces to 60% 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?

An airplane with a wingspan of 60.0 m flies parallel to the Earth's surface at a point where the downward component of the Earth's magnetic field is 0.400 * l0-4 T. If the induced potential between wingtips is 0.600 V, what is the plane's speed?

Magnetism had been a known phenomenon for some time before its relation to electric currents was found. That a current in a wire produces a magnetic field was discovered by:

A loop of area 0.250 m2 is in a uniform 0.0200-T magnetic field. If the flux through the loop is 3.21 * 10-3 T·m2, what angle does the normal to the plane of the loop make with the direction of the magnetic field?

A large jetliner with a wingspan of 40 m flies horizontally and due north at a speed of 300 m/s in a region where the magnetic field of the earth is 51 µT directed 24.1° below the horizontal. What is the magnitude of the induced emf between the ends of the wing?

A uniform 4.5-T magnetic field passes through the plane of a wire loop 0.20 m2 in area. What flux passes through the loop when the direction of the 4.5-T field is at a 30° angle to the normal of the loop plane?

The units T·m2/s are equivalent to:

A coil in a magnetic field encloses a flux of 0.256 T·m2 when the angle between the normal to the coil and the direction of the magnetic field is 70.0°. What flux would go through the coil if the angle were changed to 30.0°?

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:

A uniform 1.5-T magnetic field passes perpendicularly through the plane of a wire loop 0.30 m² in area. What flux passes through the loop?

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

A coil is placed in a magnetic field and has a flux $\varPsi$ _B through it. The coil is stressed so that its area reduces to 60% 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?

An airplane with a wingspan of 60.0 m flies parallel to the Earth's surface at a point where the downward component of the Earth's magnetic field is 0.400 * l0^-⁴ T. If the induced potential between wingtips is 0.600 V, what is the plane's speed?

A loop of area 0.250 m² is in a uniform 0.0200-T magnetic field. If the flux through the loop is 3.21 * 10^-3 T·m², what angle does the normal to the plane of the loop make with the direction of the magnetic field?

A uniform 4.5-T magnetic field passes through the plane of a wire loop 0.20 m²in area. What flux passes through the loop when the direction of the 4.5-T field is at a 30° angle to the normal of the loop plane?

The units T·m²/s are equivalent to:

A coil in a magnetic field encloses a flux of 0.256 T·m² when the angle between the normal to the coil and the direction of the magnetic field is 70.0°. What flux would go through the coil if the angle were changed to 30.0°?