A desk lamp which takes a regular size bulb. You could easily change it to a higher watt.
Yes, you can use a regular bulb in a 3-way lamp. You won't get the 3-way effect though, the regular bulb will just turn on and off.
It is not recommended to use a 75 watt light bulb on a lamp rated for a maximum of 60 watts. Doing so could cause the lamp to overheat, potentially leading to damage or fire hazard. It's best to use a light bulb that does not exceed the maximum wattage recommended by the lamp manufacturer.
The voltage isn't decided by the lamp, but by the supply the lamp is hooked up to.
6 watt bulb for mini lamp
A 120 volt table lamp with a 75 watt bulb will pull 0.625 amps. With a 100 watt bulb it will pull 0.833 amps. And with a modern fluorescent 13 watt bulb it will pull 0.108 amps.
40 watt light bulb
Yes. Lower wattage would be safe for the lamp wires and components.
If the socket threads of the lamp are the same then yes the bulbs can be interchanged. The 5 watt bulb will glow brighter than the 4 watt bulb. If by a 4 watt light you mean a 4 watt fixture, then it is not recommended to place a larger wattage lamp in a fixture that is rated by the manufacturer at a specific operating wattage
As long as the lamp holder will take the larger wattage lamp and the current of the circuit is sized to take the larger current then yes, the lamps should be interchangeable.
The wattage of a lamp can vary depending on the type of bulb used. A standard incandescent bulb typically ranges from 40 to 100 watts, while LED bulbs usually range from 4 to 20 watts. It's important to check the specific wattage of the bulb you are using to determine the overall power consumption of the lamp.
As per the formula for power (Power (Watt) = Voltage (V) x Current (i) & Resistance (R) = V / i), 25w lamp bulb would have higher resistance compared to that of 5w lamp bulb.