Question 1

A long, straight wire is in the same plane as a wooden, non-conducting loop. The wire carries an increasing current I in the direction shown in the figure.

Accepted Answer

A) There will be no induced emf and no induced current. 
B) There will be a counterclockwise induced emf, but no induced current. 
C) There will be a clockwise induced emf, but no induced current. 
D) There will be a clockwise induced current in the loop. 
E) There will be a counterclockwise induced current in the loop. 
A) There will be no induced emf and no induced current. 
B) There will be a counterclockwise induced emf, but no induced current. 
C) There will be a clockwise induced emf, but no induced current. 
D) There will be a clockwise induced current in the loop. 
E) There will be a counterclockwise induced current in the loop.

Question 2

Two coils, 1 and 2, with iron cores are positioned as shown in the figure. Coil 1 is part of a circuit with a battery and a switch.  
-Assume that S has been closed for a long time. Which one of the following changes will not result in an induced current in coil 2 that flows from left to right through R.

Accepted Answer

A) Coil 1 and its core are moved toward A. 
B) Coil 2 and its core are moved toward B. 
C) Coil 2 and its core are moved toward C. 
D) The switch S is opened. 
E) The iron core is removed from coil 1. 
A) Coil 1 and its core are moved toward A. 
B) Coil 2 and its core are moved toward B. 
C) Coil 2 and its core are moved toward C. 
D) The switch S is opened. 
E) The iron core is removed from coil 1.

Question 3

A magnetic field is directed perpendicular to the plane of a 0.15-m × 0.30-m rectangular coil consisting of 240 loops of wire. To induce an average emf of -2.5 V in the coil, the magnetic field is increased from 0.1 T to 1.8 T during a time interval $\Delta$t. Determine $\Delta$t.

Accepted Answer

A) 0.053 s 
B) 0.13 s 
C) 12 s 
D) 6.4 s 
E) 7.3 s 
A) 0.053 s 
B) 0.13 s 
C) 12 s 
D) 6.4 s 
E) 7.3 s

Question 4

Which of the following units are equivalent to those of motional emf?

Accepted Answer

A) T . m/s 
B) V . m2/s 
C) J/s 
D) A . $\varOmega$ 
E) T . m 
A) T . m/s 
B) V . m2/s 
C) J/s 
D) A . $\varOmega$ 
E) T . m

Question 5

A loop with a resistance of 4.0 $\varOmega$ is pushed to the left at a constant speed of 2.0 m/s by a 24 N force. At the instant shown in the figure, the loop is partially in and partially out of a uniform magnetic field. An induced current flows from left to right through the resistor. The length and width of the loop are 2.0 m and 1.0 m, respectively.  
-What is the direction of the magnetic field?

Accepted Answer

A) to the left 
B) to the right 
C) out of the paper 
D) into the paper 
E) toward the top of the page 
A) to the left 
B) to the right 
C) out of the paper 
D) into the paper 
E) toward the top of the page

Question 6

A circular copper loop is placed perpendicular to a uniform magnetic field of 0.75 T. Due to external forces, the area of the loop decreases at a rate of 7.26 × 10-3 m2/s. Determine the induced emf in the loop.

Accepted Answer

A) 3.1 × 10-4 V 
B) 6.3 × 10-4 V 
C) 1.2 × 10-3 V 
D) 5.4 × 10-3 V 
E) 3.1 V 
A) 3.1 × 10-4 V 
B) 6.3 × 10-4 V 
C) 1.2 × 10-3 V 
D) 5.4 × 10-3 V 
E) 3.1 V

Question 7

A loop is pulled with a force F to the right to maintain a constant speed of 8.0 m/s. The loop has a length of 0.15 m, a width of 0.080 m, and a resistance of 200.0 $\varOmega$. At the instant shown, the loop is partially in and partially out of a uniform magnetic field that is directed into the paper. The magnitude of the field is 1.2 T.  
-What is the induced current in the loop?

Accepted Answer

A) 0.048 A 
B) 0.024 A 
C) 7.2 × 10-3 A 
D) 3.8 × 10-3 A 
E) zero amperes 
A) 0.048 A 
B) 0.024 A 
C) 7.2 × 10-3 A 
D) 3.8 × 10-3 A 
E) zero amperes

Question 8

A sheet of copper is pulled at constant velocity v from a region that contains a uniform magnetic field. At the instant shown in the figure, the sheet is partially in and partially out of the field. The induced emf in the sheet leads to the eddy current shown. Which one of the following statements concerning the direction of the magnetic field is true?

Accepted Answer

A) The magnetic field points to the right. 
B) The magnetic field points to the left. 
C) The magnetic field points into the paper. 
D) The magnetic field points out of the paper. 
E) The direction of the magnetic field cannot be determined from the information given. 
A) The magnetic field points to the right. 
B) The magnetic field points to the left. 
C) The magnetic field points into the paper. 
D) The magnetic field points out of the paper. 
E) The direction of the magnetic field cannot be determined from the information given.

Question 9

Two coils, 1 and 2, with iron cores are positioned as shown in the figure. Coil 1 is part of a circuit with a battery and a switch.  
-Assume that S has been closed for a long time. Which one of the following statements is true if coil 2 is moved toward C?

Accepted Answer

A) There is an induced magnetic field in coil 2 that points toward B. 
B) There is an induced magnetic field in coil 2 that points toward C. 
C) There is an induced current in R that flows from right to left. 
D) There is an induced north pole at the right end of coil 2. 
E) There is no induced current in R. 
A) There is an induced magnetic field in coil 2 that points toward B. 
B) There is an induced magnetic field in coil 2 that points toward C. 
C) There is an induced current in R that flows from right to left. 
D) There is an induced north pole at the right end of coil 2. 
E) There is no induced current in R.

Question 10

Determine the energy stored in a 7.09 × 10-7 H inductor that carries a 1.50-A current.

Accepted Answer

A) 2.11 × 10-8 J 
B) 3.78 × 10-8 J 
C) 1.09 × 10-7 J 
D) 7.98 × 10-7 J 
E) 6.60 × 10-6 J 
A) 2.11 × 10-8 J 
B) 3.78 × 10-8 J 
C) 1.09 × 10-7 J 
D) 7.98 × 10-7 J 
E) 6.60 × 10-6 J

Question 11

Which one of the following combinations of units is equivalent to one henry?

Accepted Answer

A) N . m . s/C 
B) N . m . s2/C 
C) N . m . C2/s2 
D) N . m . C/s2 
E) N . m .s2/C2 
A) N . m . s/C 
B) N . m . s2/C 
C) N . m . C2/s2 
D) N . m . C/s2 
E) N . m .s2/C2

A long, straight wire is in the same plane as a wooden, non-conducting loop. The wire carries an increasing current I in the direction shown in the figure.

A magnetic field is directed perpendicular to the plane of a 0.15-m × 0.30-m rectangular coil consisting of 240 loops of wire. To induce an average emf of -2.5 V in the coil, the magnetic field is increased from 0.1 T to 1.8 T during a time interval $\Delta$ t. Determine $\Delta$ t.

Which of the following units are equivalent to those of motional emf?

A circular copper loop is placed perpendicular to a uniform magnetic field of 0.75 T. Due to external forces, the area of the loop decreases at a rate of 7.26 × 10^-³ m²/s. Determine the induced emf in the loop.

Two coils, 1 and 2, with iron cores are positioned as shown in the figure. Coil 1 is part of a circuit with a battery and a switch. -Assume that S has been closed for a long time. Which one of the following statements is true if coil 2 is moved toward C?

Determine the energy stored in a 7.09 × 10^-⁷ H inductor that carries a 1.50-A current.

Which one of the following combinations of units is equivalent to one henry?

Introduction and Mathematical Concepts

Kinematics in One Dimension

Kinematics in Two Dimensions

Forces and Newtons Laws of Motion

Dynamics of Uniform Circular Motion

Work and Energy

Impulse and Momentum

Rotational Kinematics

Rotational Dynamics

Simple Harmonic Motion and Elasticity

Fluids

Temperature and Heat

The Transfer of Heat

The Ideal Gas Law and Kinetic Theory

Thermodynamics

Waves and Sound

The Principle of Linear Superposition and Interference Phenomena

Electric Forces and Electric Fields

Electric Potential Energy and the Electric Potential

Electric Circuits

Magnetic Forces and Magnetic Fields

Alternating Current Circuits

Electromagnetic Waves

The Refl Ection of Light: Mirrors

The Refraction of Light: Lenses and Optical Instruments

Interference and the Wave Nature of Light

Special Relativity

Particles and Waves

The Nature of the Atom

Nuclear Physics and Radioactivity

Ionizing Radiation, Nuclear Energy, and Elementary Particles

Filters

Exam 22: Electromagnetic Induction

A long, straight wire is in the same plane as a wooden, non-conducting loop. The wire carries an increasing current I in the direction shown in the figure.

A magnetic field is directed perpendicular to the plane of a 0.15-m × 0.30-m rectangular coil consisting of 240 loops of wire. To induce an average emf of -2.5 V in the coil, the magnetic field is increased from 0.1 T to 1.8 T during a time interval Δ\DeltaΔ t. Determine Δ\DeltaΔ t.

Which of the following units are equivalent to those of motional emf?

A circular copper loop is placed perpendicular to a uniform magnetic field of 0.75 T. Due to external forces, the area of the loop decreases at a rate of 7.26 × 10-3 m2/s. Determine the induced emf in the loop.

Two coils, 1 and 2, with iron cores are positioned as shown in the figure. Coil 1 is part of a circuit with a battery and a switch. -Assume that S has been closed for a long time. Which one of the following statements is true if coil 2 is moved toward C?

Determine the energy stored in a 7.09 × 10-7 H inductor that carries a 1.50-A current.

Which one of the following combinations of units is equivalent to one henry?

Introduction and Mathematical Concepts

Kinematics in One Dimension

Kinematics in Two Dimensions

Forces and Newtons Laws of Motion

Dynamics of Uniform Circular Motion

Work and Energy

Impulse and Momentum

Rotational Kinematics

Rotational Dynamics

Simple Harmonic Motion and Elasticity

Fluids

Temperature and Heat

The Transfer of Heat

The Ideal Gas Law and Kinetic Theory

Thermodynamics

Waves and Sound

The Principle of Linear Superposition and Interference Phenomena

Electric Forces and Electric Fields

Electric Potential Energy and the Electric Potential

Electric Circuits

Magnetic Forces and Magnetic Fields

Alternating Current Circuits

Electromagnetic Waves

The Refl Ection of Light: Mirrors

The Refraction of Light: Lenses and Optical Instruments

Interference and the Wave Nature of Light

Special Relativity

Particles and Waves

The Nature of the Atom

Nuclear Physics and Radioactivity

Ionizing Radiation, Nuclear Energy, and Elementary Particles

Filters

A magnetic field is directed perpendicular to the plane of a 0.15-m × 0.30-m rectangular coil consisting of 240 loops of wire. To induce an average emf of -2.5 V in the coil, the magnetic field is increased from 0.1 T to 1.8 T during a time interval $\Delta$ t. Determine $\Delta$ t.

A circular copper loop is placed perpendicular to a uniform magnetic field of 0.75 T. Due to external forces, the area of the loop decreases at a rate of 7.26 × 10^-³ m²/s. Determine the induced emf in the loop.

Determine the energy stored in a 7.09 × 10^-⁷ H inductor that carries a 1.50-A current.