Like my electricity bill will come less if i keep my fan’s speed slow compared to if i keep my fan at full speed. Or its the same either slow or fast .
Fast speed does use more electricity than slow speed.
>[an average ceiling fan set on low speed uses about 0.25 amp, on medium speed about 0.4 amp, and on high speed about 0.6 amp. (https://homeguides.sfgate.com/many-amps-ceiling-fan-draw-87340.html)
It varies with fan design. There’s about a 15 watt difference between high and low speed on my vornado fan, measured with a kill-a-watt. 30-45 watts or so.
Edit: so say I run that fan 24/7, 45 watts, about 1 kilowatt in 30 days, about $4.80. so run it on low, about $3.45. so save 1.35 over a month.
The difference in your electricity bill when running a fan at all versus turning it off would be negligible to begin with, even much less so with the difference between low and high speed. That aside, the fan will use more energy on high speed because the faster the fan blades turn, the more air resistance it will encounter which will put more strain on the motor causing it to use more energy.
Yes. Just the same as if you were spinning the fan blade with a hand crank, spinning it faster requires more energy input, all other conditions being equal.