It is known that the resistance of a small light bulb is 20 ohm when it normally emits light, and the current passing through is 0.5 A. then the voltage at both ends of the small light bulb when it emits light is 0______ If the voltage of the power supply is 16 V, in order to make the small light bulb shine normally, one should be connected in series______ Ohm resistance

It is known that the resistance of a small light bulb is 20 ohm when it normally emits light, and the current passing through is 0.5 A. then the voltage at both ends of the small light bulb when it emits light is 0______ If the voltage of the power supply is 16 V, in order to make the small light bulb shine normally, one should be connected in series______ Ohm resistance

(1) ∵ I = ur, ∵ the voltage at both ends of the bulb u = IR = 0.5A × 20 Ω = 10V; (2) when the bulb lights normally, the voltage of series resistance ur = u-ul = 16v-10v = 6V, the resistance of series resistance R = URI = 6v0.5a = 12 Ω; so the answer is: 10; 12

A light bulb is marked with "6V & nbsp; & nbsp; 3W". To connect it to a 9V circuit and light normally, it needs to be connected______ Connect (fill in "string" or "parallel") with a resistance value of______ The resistance in Ω

Because the power supply voltage is greater than the normal working voltage of the small bulb, a resistor needs to be connected in series; the resistance of the bulb RL = u2lpl = (6V) 23W = 12 Ω, the voltage shared by the resistor in series is u = u total - UL = 9v-6v = 3V; the current in the normal light-emitting circuit is I = ulrl = 6v12 Ω = 0.5A; the resistance in series