Question

How does the key opened or closed effect the resistance in the circuit?

Answer 1

Answer:

Open key will not allow to pass the current from the wire

Closed key will allow it

Answer 2

Answer:

The circuit in the previous section is not a very practical one. In fact, it can be quite dangerous to build (directly connecting the poles of a voltage source together with a single piece of wire). The reason it is dangerous is that the magnitude of electric current may be very large in such a short circuit, and the release of energy may be very dramatic (usually in the form of heat). Usually, electric circuits are constructed in such a way as to make practical use of that released energy, in as safe a manner as possible.