2021-11-09
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What is “open circuit”?
We say “open circuit” when there is no connection. “Open circuit” is a break in some part of a circuit (for example a switch in the open or off position) or a fault (for example a broken wire or burnt out component).
What is “short circuit”?
A “short circuit” is a connection with very low resistance such as a wire which provides a very easy way for current. A short circuit is a fault or wrong connection.
For example, if the battery leads contact one another they create a connection with very low resistance and make a short circuit. Current will flow though this short circuit instead through the circuit. This stops the cir- cuit working. Short circuit can be the cause of a fire, because large current flows through the leads and the battery, and they will become very hot.
Voltage and current (complete circuit)
Current can flow when the switch is closed and the circuit is com- plete. The lamp is glowing.
Voltage but no current (open circuit)
Current cannot flow because the switch is open and the circuit is broken. The lamp is not glowing.
No voltage and no current (open circuit, no voltage source)
Current cannot flow because without the cell there is no source of voltage. The lamp is not glowing.
Exercise 1. Answer the questions
1. What is electricity?
2. What circuit is called complete?
3. What happens if a short circuit takes place in an electric circuit?
4. What are the basic components of any electric circuit?
5. In which circuit can there be voltage but no current?
Exercise 2. Translate into English
1. Когда переключатель выключен, цепь разомкнута и лампа не горит.
2. Когда переключатель включен, электричество течет по цепи и лампа горит.
3. Если лампа перегорает, цепь размыкается.
4. Электрический ток течет через провода от батареи к элемен- там цепи и назад к батарее.
5. Короткое замыкание может быть причиной пожара.
