Electronics - Voltage and Current - Discussion

See. You cannot have a current flow in open air.

That's why the birds don't get shocks while touching only one wire.

Instead if the bird is a BAT and touches two wire due to which the current gets one more path to travel except itself i.e. through the BAT's body. And poor bat dies. !

Same phenomenon is applied here. If a circuit is open then current cannot flow through it as the flow of electrons will not get any path for their conduction. Until and unless it is connected with a wire or some other conducting material connected with the opposite terminal of the battery.

An open circuit leads to zero current whatever be the voltage so not A,

An insulated circuit will lead to a flow of negligible current however large the voltage be, so not B,

A high change in voltage is required to influence a small current in high resistance, so C is not viable.

Thus the closed circuit in which current flows on providing a potential difference and has no restrictions of insulation or high resistance is the most viable option.

@Moeen.

The flow of electrons is called current. The protons are inside the nucleus so they do not flow. They are immobile. The positive charge that is said to flow are holes which represent the empty spaces left by electrons. So they flow in the direction opposite to the flow of electrons. Since current also flows opposite to the flow of electrons, the direction of flow of protons is equal to the direction of flow of current.

Consider voltage as water in a tank and current as water flowing in pipe.

Force of water flowing in pipe(current) is related to amount of water in tank(voltage).

Water flow in pipe(current) depends on water in tank(voltage) only when pipe is connected to tank(closed cicuit).

when pipe breakes(open cicuit) water flow stopes at tap(current=0)

Consider voltage as water in a tank and current as water flowing in pipe.

Force of water flowing in pipe(current) is related to amount of water in tank(voltage).

Water flow in pipe(current) depends on water in tank(voltage) only when pipe is connected to tank(closed cicuit).

when pipe breakes(open cicuit) water flow stopes at tap(current=0)

Current flows in closed circuits only. At open terminals voltage is infinity that is maximum, where as current will be zero. In case short circuits, voltage is zero and current will be maximum.

So, voltage is inlfuence the current in closed circuits only.

When the circuit is open, there is no path for flow of current. If the circuit is in short condition then there is o voltage. Voltage and current both are present when a circuit is in closed condition. So closed condition is the right answer.

Open circuit has infinite resistance and we know that resistance is opposition to flow of current if opposition to current is infinite then current is zero so we have ohms law

(i.e) v/i=r if i=o then v=o.

So circuit must be closed.

From Ohm's law,
Current(I)=Voltage(V)/Resistance(R)

So, current is inversely proportional to resistance. Lower the resistence & the current will increase, if voltage is constant. This can happen only in case D.

As per ohms law voltage is directly proportional to current, there is no current in open circuit hence there is no effect of voltage in open circuit. There is effect of voltage in closed because current exists in closed circuit.