A $$1 \text{ m}$$ long copper wire carries a current of $$1 \text{ A}$$. If the cross section of the wire is $$2.0 \text{ mm}^2$$ and the resistivity of copper is $$1.7 \times 10^{-8} \Omega \text{ m}$$. The force experienced by moving electron in the wire is ______ $$\times 10^{-23} \text{ N}$$. (Charge of electron $$= 1.6 \times 10^{-19} \text{ C}$$)

We are given a copper wire of length $$L = 1 \text{ m}$$, carrying current $$I = 1 \text{ A}$$, with cross-section area $$A = 2.0 \text{ mm}^2 = 2.0 \times 10^{-6} \text{ m}^2$$ and resistivity $$\rho = 1.7 \times 10^{-8} \text{ } \Omega \text{ m}$$. We need to find the force on a moving electron.

The resistance of the wire is:

$$R = \frac{\rho L}{A} = \frac{1.7 \times 10^{-8} \times 1}{2.0 \times 10^{-6}} = 8.5 \times 10^{-3} \text{ } \Omega$$

The voltage across the wire is:

$$V = IR = 1 \times 8.5 \times 10^{-3} = 8.5 \times 10^{-3} \text{ V}$$

The electric field inside the wire is:

$$E = \frac{V}{L} = \frac{8.5 \times 10^{-3}}{1} = 8.5 \times 10^{-3} \text{ V/m}$$

The force experienced by an electron in the electric field is:

$$F = eE = 1.6 \times 10^{-19} \times 8.5 \times 10^{-3}$$

$$F = 13.6 \times 10^{-22} = 136 \times 10^{-23} \text{ N}$$

The force experienced by the moving electron is $$136 \times 10^{-23} \text{ N}$$.