In a series circuit, the greater the total resistance, the less the total power of the circuit? A DC motor, with rated voltage of 220 V, normal working resistance of 40 ohm and electric power of 60 kW, what is its normal working current? In the series circuit, it is known that the power supply voltage is 4.5 V, the range of the voltmeter is 0-3 V, the maximum resistance of the sliding rheostat R is 10 ohm, and the small bulb L is marked with the word "2.5V 1.25W". After closing the switch, when the small bulb lights normally, what is its resistance? What is the resistance of the sliding rheostat connected to the circuit / if the resistance of the small bulb remains unchanged, in this circuit, What is the minimum power of a small light bulb? In a series circuit, if the total resistance in the circuit is three times of the original by moving the slide P, how much heat is generated in the same time?

In a series circuit, the greater the total resistance, the less the total power of the circuit? A DC motor, with rated voltage of 220 V, normal working resistance of 40 ohm and electric power of 60 kW, what is its normal working current? In the series circuit, it is known that the power supply voltage is 4.5 V, the range of the voltmeter is 0-3 V, the maximum resistance of the sliding rheostat R is 10 ohm, and the small bulb L is marked with the word "2.5V 1.25W". After closing the switch, when the small bulb lights normally, what is its resistance? What is the resistance of the sliding rheostat connected to the circuit / if the resistance of the small bulb remains unchanged, in this circuit, What is the minimum power of a small light bulb? In a series circuit, if the total resistance in the circuit is three times of the original by moving the slide P, how much heat is generated in the same time?

1. In the series circuit, the greater the total resistance, the smaller the total power of the circuit, correct!
2.I=P/U=60/220=0.27A
3. The resistance of the small light bulb is: RL = UL ^ 2 / PL = 2.5 ^ 2 / 1.25 = 5 Ω when it lights normally
The normal working current of small bulb is: I = PL / UL = 1.25/2.5 = 0.5A
The resistance value of sliding rheostat access circuit is: r = (4.5-2.5) / 0.5 = 4 Ω
If the resistance of the small bulb does not change, the minimum power of the small bulb in this circuit is 0
PLm=I'^2RL=[U/(RL+RM)]^2*RL=[4.5/(5+10)]^2*5=0.45W
4.Q=U^2t/R
Then: Q '= u ^ 2T / (3R) = 1 / 3Q