PHYS 1260 EXAM 2 - 4 QUESTIONS WITH VERIFIED
ANSWERS
what is electromagnetic induction? - Answers - induces voltage by changing the
magnetic field strength in a coil of wire
any path along which electrons can flow from the negative terminal to the positive
terminal is what? - Answers - - a circuit
circuits are connected in what two ways? - Answers - 1. series
2. parallel
1. series - Answers - - forms a single pathway for electron flow between the terminals of
the battery, generator or wall outlet
2. parallel - Answers - - forms branches, each of which is a separate path for the flow of
electrons
who discovered electromagnetic induction? - Answers - Faraday and Henry
three characteristics of a series circuit - Answers - 1. electric current through a single
pathway
2. total resistance to current is the sum of individual resistances
3. current is equal to the voltage supplied by the source divided by the total resistance
of the circuit
electromagnetic induction: how can induced voltage be increased? (2) - Answers - 1.
increasing the number of loops in a coil
2. increasing the speed of the magnet entering and leaving the coil
electromagnetic induction: what produces a greater voltage...slow or rapid motion? -
Answers - - rapid = greater voltage
- slow = hardly any voltage
electromagnetic induction: what are the two ways that voltage will be produced in a wire
loop? - Answers - 1. the magnetic field moves past the wire
2. the wire moves through the magnetic field
electromagnetic induction: when a magnet is plunged into a coil with twice as many
loops as another, how much voltage is induced? - Answers - - twice as much voltage
electromagnetic induction: if the magnet is plunged into a coil with 3 times as many
loops, how much voltage is induced? - Answers - - 3 times as much voltage
, What does Faraday's law state? - Answers - - the induced voltage in a coil is
proportional to the number of loops, multiplied by the rate at which the magnetic field
changes within these loops
Faraday's law: what is the amount of current produced by electromagnetic induction
dependent on? (3) - Answers - 1. resistance of the coil
2. circuit that it connects
3. induced voltage
Faraday's Law: why is it more difficult to push a magnet into a coil with many loops? -
Answers - - because the magnetic field of each current loop resists the motion of the
magnet
Most of the waves in the electromagnetic spectrum are
A) red light.
B) blue light.
C) green light.
D) invisible. - Answers - D) invisible.
Electromagnetic waves consist of
A) the compression and refraction of electromagnetic pulses.
B) oscillating electric and magnetic fields. C) particles of light energy.
D) high-frequency sound waves. - Answers - B) oscillating electric and magnetic fields.
Which of the following cannot travel in a vacuum (free space)?
A) Light wave
B) Sound wave
C) Radio wave
D) [all of these]
E) [none of these] - Answers - B) Sound wave
The fact that you can see stars in the nighttime sky is evidence that
A) our atmosphere is transparent to visible light.
B) light can travel in a vacuum.
C) [both of these]
D) [neither of these] - Answers - C) [both of these]
Light is reflected when
A) electron clouds of atoms are energized.
B) atomic nuclei are made to vibrate.
C) incident light is returned into the medium from which it came.
D) electromagnetic waves emanate from matter. - Answers - C) incident light is returned
into the medium from which it came.
ANSWERS
what is electromagnetic induction? - Answers - induces voltage by changing the
magnetic field strength in a coil of wire
any path along which electrons can flow from the negative terminal to the positive
terminal is what? - Answers - - a circuit
circuits are connected in what two ways? - Answers - 1. series
2. parallel
1. series - Answers - - forms a single pathway for electron flow between the terminals of
the battery, generator or wall outlet
2. parallel - Answers - - forms branches, each of which is a separate path for the flow of
electrons
who discovered electromagnetic induction? - Answers - Faraday and Henry
three characteristics of a series circuit - Answers - 1. electric current through a single
pathway
2. total resistance to current is the sum of individual resistances
3. current is equal to the voltage supplied by the source divided by the total resistance
of the circuit
electromagnetic induction: how can induced voltage be increased? (2) - Answers - 1.
increasing the number of loops in a coil
2. increasing the speed of the magnet entering and leaving the coil
electromagnetic induction: what produces a greater voltage...slow or rapid motion? -
Answers - - rapid = greater voltage
- slow = hardly any voltage
electromagnetic induction: what are the two ways that voltage will be produced in a wire
loop? - Answers - 1. the magnetic field moves past the wire
2. the wire moves through the magnetic field
electromagnetic induction: when a magnet is plunged into a coil with twice as many
loops as another, how much voltage is induced? - Answers - - twice as much voltage
electromagnetic induction: if the magnet is plunged into a coil with 3 times as many
loops, how much voltage is induced? - Answers - - 3 times as much voltage
, What does Faraday's law state? - Answers - - the induced voltage in a coil is
proportional to the number of loops, multiplied by the rate at which the magnetic field
changes within these loops
Faraday's law: what is the amount of current produced by electromagnetic induction
dependent on? (3) - Answers - 1. resistance of the coil
2. circuit that it connects
3. induced voltage
Faraday's Law: why is it more difficult to push a magnet into a coil with many loops? -
Answers - - because the magnetic field of each current loop resists the motion of the
magnet
Most of the waves in the electromagnetic spectrum are
A) red light.
B) blue light.
C) green light.
D) invisible. - Answers - D) invisible.
Electromagnetic waves consist of
A) the compression and refraction of electromagnetic pulses.
B) oscillating electric and magnetic fields. C) particles of light energy.
D) high-frequency sound waves. - Answers - B) oscillating electric and magnetic fields.
Which of the following cannot travel in a vacuum (free space)?
A) Light wave
B) Sound wave
C) Radio wave
D) [all of these]
E) [none of these] - Answers - B) Sound wave
The fact that you can see stars in the nighttime sky is evidence that
A) our atmosphere is transparent to visible light.
B) light can travel in a vacuum.
C) [both of these]
D) [neither of these] - Answers - C) [both of these]
Light is reflected when
A) electron clouds of atoms are energized.
B) atomic nuclei are made to vibrate.
C) incident light is returned into the medium from which it came.
D) electromagnetic waves emanate from matter. - Answers - C) incident light is returned
into the medium from which it came.
