Solid-State Electronics
Practice Test
1.
What happens to conductors as the temperature rises?
a.
nothing
b.
The resistance is reduced.
c.
The conductivity increases.
d.
The conductivity is reduced.
Hint
2.
What happens to atomic energy levels when many atoms are brought together?
a.
They vibrate.
b.
They disappear completely.
c.
They split into broad bands with forbidden gaps.
d.
They join into one energy level.
Hint
3.
In Figure 29-20, what resistor should be used to increase the current to 25 mA? Assume that the potential drop across the LED is still 1.2 V.
a.
120 Ω
b.
300 Ω
c.
192 Ω
d.
240 Ω
Hint
4.
If the battery in Figure 29-18 were reversed, which lamp(s) would light?
a.
L
2
only
b.
L
1
only
c.
both lamps
d.
neither lamp
Hint
