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