Because thereâs nothing wrong with doing it as a hobby. Itâs also going to take you a long time to get to full-time status. It took me just shy of 3 years to get to the point where we completely replaced our household income with our photography income, and that was considered fast.
In a series circuit, the voltage across a resistor is directly proportional with its resistance (Et= I(Rint+R). That means in a series circuit the voltage across the resistor will increase when the resistance in increased, while the current will reduce. A power source has internal resistance (Rint) which will be in series with the resistor R. So even though your resistor is connected across the power supply, the internal resistance Rint is in series with it.
Temperature affects the resistance of a circuit by causing it to allow electrons flow more or less freely, and therefore the amount of energy expended will change with temperature. The answer is yes but there are many forms of batteries. You should refer to IEEE Std 450-1995 for flooded lead acid batteries.