Electronics Final Exam Test 1
If V= 25V and R= 50 kO in figure 3-1, the current equals...
0.5 mA
What is the total supply voltage if 16V and 12V sources are wired in series opposing?
4 V
The basic difference between a fuse and a circuit breaker is that:
A circuit breaker is reusable
Which is the correct formula for finding power?
All of these
If R4 shorts in figure 6-2, VR5...
Decreases
0.0047 amps can be expressed in metric units as 47 uA.
False
Electrons attract each other
False
If a 1/4 W resistor and a 1/2 W resistor are wired in series, they can safely dissipate 3/4 W.
False
If one branch of a parallel circuit opens, the total resistance decreases.
False
If the voltage applied to a circuit doubles, then power dissipation doubles.
False
If three equal resistors are connected in parallel across 12 V, each resistor drops 4 V.
False
A short in a series circuit results in:
Increased or maximum current flow
If R2 shorts in figure 4-1, the total circuit power...
Increases
If the voltage is suddenly switched off in Figure 3-1, ...
The current will suddenly drop to 0 A
How does the magnetic field change around a conducting wire if the current increases?
The field grows stronger
A magnetic field around a conductor is a good indication that current is flowing.
True
If a circuit's supply voltage is 15V and its resistance is 4700 ohms, its current is 3.19 mA.
True
If one branch of a parallel circuit shorts, the total resistance decreases.
True
To measure the current through a resistor, place the ammeter so the current must pass through the meter.
True
In figure 2-2, the voltage Vgh is the same as...
V R8
If some turns of wire are removed from an electromagnet, the magnetic field will...
be less than the original electromagnet
Refer to figure 6-5. Determine the amount of current flow through R2 with the flowing component parameters. Vs1=10,
1.37 mA
Calculate the current in figure 4-1 if VR1=16V, R1=10kO, R2= 10kO, and R3= 15kO
1.6 mA
Pico is what in relation to micro?
1/1,000,000th
A 50kO potentiometer is connected across a 15V source. If the voltage from the wiper to the lower end of the potentiometer is 3.2V, what is the resistance of that lower part?
10.7 kO
If a 330 O resistor dissipates 2W, its voltage drop equals...
25.7 V
Add 21 mA and 8000 uA and express the result in milliamperes.
29 mA
If R1=4.7 kO, R2=3.3 kO and R3= 1kO in figure 6-1, the total resistance equals...
5467 ohms
If a 5 A and a 3 A enter a junction from two separate paths, how much current flows out of the junction
8 A
If a 4.7 kO resistor, a 3.3 kO resistor and a 5.43 kO resistor are connected in parallel across a 50V source, what is the current through the 5.43 kO resistor?
9.21 mA
If a resistor is rated at 1/2 W, it...
Can safely dissipate 1/2 W of power
If the current in a circuit equals 0 A, it is likely that the...
Circuit is open
A weber is unit of...
magnetic flux
The symbol for electrical charge is...
Q
The term reluctance in magnetic circuits is like the term .... in electrical circuits.
Resistance
The principal difference between a solenoid and a relay is that:
solenoids do mechanical work, relays do electrical work
