Electronics

which instrument measures electrical resistance?

ohmmeter

AC stands for …

alternating current

a 2-volt source is connected across a 4-ohm resistor, current is…

3 A

two 6-ohm resistors connected in series have total resistance of…

12 Ω

two equal 6-ohm resistors connected in parallel have equivalent resistance of…

3 Ω

if resistance doubles while voltage stays constant, current…

is halved

which component normally conducts primarily in one direction?

diode

a relay is best described as …

an electrically operated switch

a fuse protects a circuit by …

opening when excessive current melts its element

compared with a fuse, a circuit breaker can normally be …

reset after the fault is corrected

a capacitor stores energy primarily in …

an electric field

an inductor stores energy primarily in …

a magnetic field

a transformer operated through

electromagnetic induction

a typical battery supplies …

DC

an open circuit is …

a broken current path

a short circuit is generally …

an unintended low-resistance path

which meter is used to measure current?

ammeter

which meter measures potential difference across two points?

voltmeter

current flowing through a conductor creates …

a magnetic field

if one branch opens in a paralled circuit, other intact brnches generally …

can continue to conduct

a 24 V source drives 3 A through a load, the load resistance is …

8 Ω

a device uses 12 V and draws 2 A, its electrical power is …

24 W

which material is generally a good electrical conductor?

copper

why should power be removed before using an ohmmeter on a component?

the meter’s reading can be wrong and the meter / circui may be damaged

in a series circuit with three lamps, one lamp burns open, what normally happens to the other lamps?

they go out because the path is broken