In May of 2019 the definition of the ampere, the SI unit of current, was changed - Leaving Cert Physics - Question d - 2020

To calculate the current, we first need to find the total charge that passes in 30 minutes:

1. Calculate the total charge (Q):

   $Q = n imes e$
   where n = number of moles and e = elementary charge (approximately $1.6 imes 10^{-19} C$).

   $Q = (6.0 imes 10^{23}) imes (1.6 imes 10^{-19}) = 96,000 C$

2. Convert 30 minutes to seconds:

   $30 ext{ minutes} = 30 imes 60 = 1800 ext{ seconds}$

3. Use the formula for current (I):

   $I = \frac{Q}{t} = \frac{96000 C}{1800 s} = 53.3 A$

The phenomenon of two parallel current-carrying conductors exerting a force on each other occurs due to the magnetic fields generated by the current flowing through the wires. Each wire generates a magnetic field in the surrounding space, and when the two wires are placed parallel to each other, they affect each other's magnetic fields, resulting in a force. If the currents flow in the same direction, the wires attract each other; if they flow in opposite directions, they repel each other.

1. Power supply and U-shaped foil: Set up a power supply that can deliver current and connect two U-shaped pieces of conductive foil to the power supply, ensuring they are parallel to each other and close enough for interaction.

2. Allow current to flow: Turn on the power supply to allow current to flow through both pieces of foil.

3. Observe the movement of foil: You should observe the U-shaped foils either attract or repel each other depending on the direction of the currents, thus demonstrating the force generated between the parallel conductors.