What would you like to do?
What uses more electricity - keeping a fridge door open for a while or constantly opening and closing it during this time?
Every time you open your fridge door - or indeed your freezer's door - it allows cold air to fall out onto the floor of the room. If this is allowed to happen for more t…han a few moments the thermostat inside the fridge or freezer, sensing that too much cold air has gone, will turn on the fridge's motor and compressor pump to cool down the new air. The more the compressor pump and its motor are forced to run unnecessarily, the more electricity would be used, with the consequence that the money to pay for that electricity would simply be wasted. Knowing those "facts of life" it should be easy to understand why it is better to keep the door closed as much as possible instead of leaving it to hang open for more than the short time it takes to load or unload food from the fridge.
http://www.booneelectric.coop/coop/tips2.htm According to this webpage the average garage door opener is 800 watts and uses 6¢/hr worth of electricity (based on a …8 cents per kilowatt hour electric rate).
.. The device used to open and close an electric circuit is a switch.
A device used to open and close an electric circuit could be any number of types of switches, a contactor, a relay, a transistor, a silicon controlled rectifier (SCR).
An electric can opener is a household appliance which uses electricity. It is powered by a motor which includes a permanent magnet so it can spin the same way consistently. It…'s blades spin so slice tin or can, open. It is usually found as well as used in the kitchen...
An electromagnet if formed by pushing current through a coil. If the circuit is truly open, current will cease to flow, thus no electromagnet.
The device is called a switch.
which electric element should be used so as to open the closed electric circuit
A switch, circuit breaker, fuse, or switching transistor can do that.
A switch, when in the open position, the charged particles can't flow through the circuit, but once you close the switch, the charged particles can flow
To open cans electrically, instead of using a manual crank.
The electricity will flow from higher potential to lower potential in a closed circuit.
A number of electric can openers are made in the US including the EZ-DUZ-IT and, for heavier duty work, the Edlund 266 (see Sources and related links section below). ANSWER 2…: There is only one electric can opener still made here and it is the Edlund 266. The EZ_DUZ_IT can opener is a manual can opener, not an electric.