Solid-State Electronics
Practice Test
1.
Calculate the radius of the orbital associated with the energy level
E
5
of the hydrogen atom. Use
h
2/(4
π
A24
2
Kmq
2
= 5.30×10
-11
m.
a.
1.33×10
-10
m
b.
1.33×10
-9
m
c.
1.91×10
-10
m
d.
1.91×10
-9
m
Hint
2.
Einstein predicted that photons had two properties of particles: __________ and __________.
a.
energy; momentum
b.
energy; mass
c.
momentum; diffraction
d.
mass; momentum
Hint
3.
In the situation depicted in Figure 27-12, if the electron's initial kinetic energy is doubled, what stopping potential would be required?
a.
5.0 V
b.
25.0 V
c.
10.0 V
d.
2.5 V
Hint
4.
What happens to the secondary current in a step-up transformer?
a.
It remains the same.
b.
It is not affected.
c.
It decreases.
d.
It increases.
Hint
5.
A voltmeter reads 450 V across two charged, parallel plates that are 5.0 cm apart. What is the electric field between them?
a.
9.0×10
3
N/C
b.
9.0×10
1
N/C
c.
9.0×10
2
N/C
d.
1.1×10
-4
N/C
Hint
6.
What device uses stimulated emission to produce an avalanche of photons, having the same wavelength and their minima and maxima at the same times?
a.
spectroscope
b.
semiconductor
c.
diffraction grating
d.
laser
Hint
7.
__________ is (are) generated when a piece of metal moves through a magnetic field.
a.
Voltage drop
b.
Lenz's laws
c.
Eddy currents
d.
EMF
Hint
8.
Which of the following represents the Bohr quantization condition?
a.
r
/
λ
=
h
/2
π
b.
2
n
=
λπr
c.
nλ
= 2
πr
d.
2
πrh
=
nλ
Hint
9.
For the situation depicted in Figure 27-13, what would the kinetic energy of the ejected electrons be if the incident radiation had a wavelength of 200.0 nm and the metal had a work function of 2.56 eV?
a.
1.25 eV
b.
2.40 eV
c.
2.56 eV
d.
3.64 eV
Hint
10.
Why are dopants added to intrisinc semiconductor materials?
a.
to increase the forbidden gap
b.
to increase conductivity
c.
to increase resistance
d.
to make semiconductors electrically neutral
Hint
11.
If the battery in Figure 29-18 were reversed, which lamp(s) would light?
a.
L
2
only
b.
neither lamp
c.
both lamps
d.
L
1
only
Hint
12.
An alternating current source produces changing currents in a wire connected to it. This wire generates electromagnetic fields. What is this wire called?
a.
a polarizer
b.
a capacitor
c.
an antenna
d.
an oscillator
Hint
13.
A 6.4-
μ
F capacitor is first charged so that the electric potential difference is 5.0 V. How much additional charge is needed to increase the electric potential difference to 12.0 V?
a.
7.7×10
-5
C
b.
4.5×10
-5
C
c.
4.5×10
5
C
d.
7.7×10
5
C
Hint
14.
The force on an electron from a magnetic field is __________.
a.
opposite the direction indicated by the third right hand rule
b.
so small it cannot be measured
c.
in the same direction as indicated by the third right hand rule
d.
in the same direction as the magnetic field
Hint
15.
The work function for a certain element is 2.87 eV. What is its threshold wavelength?
hc
= 1240 eV·nm
a.
356 nm
b.
446 m
c.
495 nm
d.
432 nm
Hint
16.
__________ lines are dark lines in the spectrum of sunlight.
a.
Fraunhofer
b.
Omission
c.
Radiated
d.
Emitted
Hint
17.
In Figure 29-17c, how does the current go through the diodes?
a.
to the right for the top one, the left for the bottom one
b.
to the left for the top one, the right for the bottom one
c.
no current through the top one, to the left for the bottom one
d.
to the right for the top one, no current through the bottom one
Hint
18.
What happens to conductors as the temperature rises?
a.
The resistance is reduced.
b.
The conductivity increases.
c.
The conductivity is reduced.
d.
nothing
Hint
19.
An electron moving at 5.6×10
7
m/s travels through a uniform magnetic field of 1.4 T at right angles to the field. How strong is the force that acts on the electron?
a.
1.5×10
-11
N
b.
-1.3×10
-11
N
c.
2.2×10
-11
N
d.
-3.7×10
-11
N
Hint
20.
What occurs in a material that has the property of piezoelectricity?
a.
It amplifies sound waves.
b.
It produces a beam of light when it enters a magnetic field.
c.
It emits infrared radiation.
d.
It bends or deforms when a voltage is applied across it.
Hint
