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berkeman said:The LED forward voltage drop is usually more like 2V for a red LED, isn't it?
vk6kro said:NiCd batteries are also very sensitive to overcharging. Give them 100 mA for 2 days and they will probably be destroyed. This charger has no timer or overcharging detector, so it is almost guaranteed to destroy its batteries. Anybody can just put the batteries on charge and forget about them until it is too late.
The relationship between ohms and wattage in a resistor is defined by Ohm's Law, which states that the voltage across a resistor is directly proportional to the current passing through it, and inversely proportional to the resistance of the resistor. This means that as the resistance (measured in ohms) increases, the wattage (measured in watts) also increases.
The wattage of a resistor can be calculated using the formula P=VI, where P is the power (wattage), V is the voltage, and I is the current. Alternatively, you can use the formula P=I^2R, where R is the resistance in ohms.
The standard unit of measurement for resistance is the ohm (symbol: Ω). This unit is named after the German physicist Georg Ohm, who first discovered the relationship between voltage, current, and resistance.
Yes, a resistor can have a wattage rating higher than its stated value. This is known as the power rating or power dissipation rating, and it indicates the maximum amount of power the resistor can safely handle without overheating.
Resistors have different wattage ratings because they are designed to handle different amounts of power. Higher wattage resistors can handle more power without getting damaged, while lower wattage resistors are more suitable for circuits with lower power requirements. The wattage rating is also an important factor to consider when selecting a resistor for a specific application.