Suppose you have an electrical device that dissipates 500J of energy as heat in 10 minutes and the current passing through it is 2A. What is the resistance of the device?

(a)  

Suppose you have an aluminum wire with a resistance of 4Ω and a resistivity of $$2.82x10^{-8}\Omega m^2$$ . What is the length of this cable if its cross-sectional area is $$1.5x10^{-6}m^2$$

(a)  

Imagine that you have a resistor with a resistance of 15Ω and it dissipates 1000J of energy as heat. If the current passing through it is unknown, but the time is 5 minutes, what is the current passing through the resistor?

(a)  

If you have a bar of conductive material with a length of 2m and a cross-sectional area of $$0.02m^2$$ , and you want the resistance of this bar to be 25 Ω, what should be the resistivity of the material?

(a)  

Suppose you have a 10Ω resistor and a current of 5A passing through it for 2 minutes. How much energy is dissipated as heat in the resistor during this time?

(a)  

Imagine that you have a circuit with a 20Ω resistor. If a current of 2A flows through this circuit for 30 seconds, how much energy is dissipated as heat?

(a)