Author Question: A simple electric doorbell probably uses ________ to ring the bell. A) an electromagnet B) ... (Read 7 times)

AEWBW · **on:** Jul 28, 2018

A simple electric doorbell probably uses ________ to ring the bell.

A) an electromagnet B) transistor
C) a DPDT switch D) a permanent magnet

Question 2

A relay is a device that ________.

A) isolates the actuating signal from the control signal
B) uses an electromagnet to open and close contacts
C) has a coil to actuate some contacts that control other circuits
D) all of these