Find the Resistance of A copper wire 5 meters long with a radius of 5mm that has a battery connected across the ends with a potential difference of 12V. Resistivity of copper is 1.7 x 10^-8 ohm Meters.
Next question is to find current (I) in the wire if it’s connected to a battery with a voltage of 12V, use ohm’s law.
What is the resistance of the wire? What is the current in the wire?

Consider a large isothermal enclosure that is maintained at a uniform temperature of 2000 k. calculate the emissive power of the radiation that emerges from a small aperture on the enclosure surface. what is the wavelength ? , below which 10% of the emission is concentrated? what is the wavelength ? 2 above which 10% of the emission is concentrated? determine the wavelength at which maximum spectral emissive power occurs. what is the irradiation incident on a small object placed inside the enclosure?