A circuit breaker uses an electromagnet.
Explain why the current is cut off by a circuit breaker if it is larger than a certain value.
Actually, most household circuit breakers do NOT use magnets. Take one apart and investigate, they use a bimetallic strip which heats when excess current flows, bends, and trips a spring loaded latch holding the actuator arm On, moving it to the off position. It is amazing what one discovers when one looks.
There are some different types of large circuit breakers which do use electromagnets, or a combination of electromagnets and bimetalic strips. A small minority of these release the switch latch by excess current going through the electromagnetic coil. In nearly all cases the actuator lever is spring or hydraulic loaded to close.
Most circuit breakers do not use just an electromagnet, because current surges can trip those easily, and one doesn't want that very often.
The design challenge in circuit breakers is not the design of the tripping of the latch mechanism, any high school student could do that. The issue really difficult is that as the contacts are opened, and gap exists, wherein an arc developes. Arcs ionize air (Nitrogen,mainly), which then the ionized air makes a very easy path for electricity to travel (as in a lighting bolt). So even with the contacts open, electricty still flows easily across an "air" gap, when it shouldn't. So the design challence is to snuff out the arc as the contacts are opened. Usually this is done with a magnetic field which you know electricity flowing in a magnetic field has a force on it. So if designed correctly, the arc develops, and then that current flows through an electromagnetic coil, which creates a strong magnetic field perpendicular to the arc, and the arc is "blown" away from the contacts, and extinguished. Neat engineering goes into this, as it cannot ever fail, or the switch will never stop electric flow, even with the switch in the "off" position.
So all the engineering and thought is focused on the arc suppression, rather than the latch release mechanism.
Take apart a few circuit breakers, any electric shop has some old ones laying around they will give you.
Thanks for asking.
I don't particularly like circuit breakers tripping. It usually means I have a lot of work to do and money out the flare stack. Of course if it doesn't work then the fire department has work to do, and I have a lot of work to do.
To understand why a circuit breaker cuts off the current when it exceeds a certain value, it's important to know how a circuit breaker works.
A circuit breaker is an electrical switch designed to protect an electrical circuit from damage caused by excessive current. It typically consists of an electromagnet, a spring-loaded mechanism, and a pair of contacts.
When the current flowing through the circuit breaker is within its normal range, the electromagnet does not generate a strong magnetic field. This allows the contacts to remain closed, enabling the current to flow smoothly through the circuit.
However, if the current exceeds a certain threshold, the electromagnet's magnetic field becomes stronger. This causes the spring-loaded mechanism to trip, separating the contacts and interrupting the flow of current.
The reason for cutting off the current is to prevent overheating and potential damage to the electrical system. When current exceeds the rated capacity of the circuit, it can lead to excessive heat generation, which can melt insulation, cause sparks or fires, and damage other components or devices in the circuit.
By tripping and cutting off the current, the circuit breaker effectively stops the flow of electricity, protecting the circuit and preventing potential hazards. It acts as a safety device that automatically disconnects the power when abnormal or dangerous conditions occur.
In summary, a circuit breaker cuts off the current when it exceeds a certain value to prevent overheating, damage to the electrical system, and potential hazards. The electromagnet's strong magnetic field triggers the mechanism to separate the contacts and interrupt the flow of current.