Electricity and Circuits Flashcards
7 cards from real Bennett Mechanical Test practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Electricity and Circuits flashcards as text
What instrument measures electrical current?
Answer: Ammeter
An ammeter measures current and is connected in series with the circuit.
If voltage stays constant and resistance increases, what happens to current?
Answer: Current decreases
By Ohm's law, current is inversely proportional to resistance at fixed voltage.
What is created around a wire when current flows through it?
Answer: A magnetic field
Current flowing through a conductor produces a magnetic field around it.
Three 4-ohm resistors are connected in series. What is the total resistance?
Answer: 12 ohms
Series resistances add, so 4 + 4 + 4 = 12 ohms.
Why are appliances in a home wired in parallel rather than series?
Answer: So each can operate independently at full voltage
Parallel wiring lets each appliance get full voltage and work independently.
What does AC stand for in electricity?
Answer: Alternating current
AC stands for alternating current, which periodically reverses direction.
What is the effect of connecting a voltmeter in series instead of parallel?
Answer: It blocks nearly all current due to high resistance
A voltmeter's high resistance in series severely limits current and gives a wrong reading.