Assertion: phone | /r/HasProperty | off-hook
Facets:
Source sentences:
text: A momentary push-button switch may be added across the 33k resistor to manually trigger the SCR so that the phone can connect when another phone is off-hook.
text: The landline telephone contains a switchhook (A4) and an alerting device, usually a ringer (A7), that remains connected to the phone line whenever the phone is "on hook" (i.e. the switch (A4) is open), and other components which are connected when the phone is "off hook".