If you want to change the hair dryer to make the temperature of hot air higher, you should connect a resistance wire to the original resistance wire

If you want to change the hair dryer to make the temperature of hot air higher, you should connect a resistance wire to the original resistance wire

If we want to change the hair dryer to make the temperature of the hot air higher, we should connect another resistance wire (in parallel) to the original resistance wire

As shown in the figure, the electromotive force of the power supply e = 7.5V, the internal resistance R = 1.0 Ω, the constant resistance R2 = 12 Ω, and the coil resistance R of the motor M = 0.5 Ω. After the switch S is closed and the motor rotates stably, the voltmeter U1 = 4V, and the current flowing through the resistance R2 is 0.5A
(1) Terminal voltage of power supply. (2) output power of motor
There is no figure to measure the voltage at both ends of the motor with U1 connected in series with R1 and in parallel with R2

1. Terminal voltage U = R2 * I2 = 12 * 0.5 = 6V
2. I total = (E-U) / r = (7.5-6) / 1 = 1.5A
Im = I1 = itotal-i2 = 1.5-0.5 = 1A
Ptotal = umim = 4 * 1 = 4W
Pthermal = im ^ 2 * RM = 1 ^ 2 * 0.5 = 0.5W
P = 4-0.5 = 3.5W
M refers to the motor

Hair dryer A is hair dryer B is heating wire
One switch S1 one switch S2 one
1 1 1
B a power supply
1 1 1
one one one one one one one one one one
One is a vertical line and the other is a horizontal line
A is the hair dryer, B is the heating wire. If S2 is only closed, the blowing is () wind;
If S1 and S2 are closed, the wind will blow out
(choose "cold" or "hot")

A is the blower, B is the heating wire. If S2 is only closed, the (cold) air is blown out;
If S1 and S2 are closed, the wind is hot
(when S2 is only closed, the heating wire doesn't work. It's only a blower, so it's cold air. However, after S2 is closed, the heating wire releases heat. When the blower rotates, the wind blows out with heat, so it's hot air.)

In order to reduce the heating power of the heating wire in the hair dryer to half of the original, we should () a, halve the voltage B, halve the current
In order to reduce the heating power of the electric heating wire in the electric hair dryer to half of the original, it should ()
A. Half the voltage B, half the current C, double the resistance D, half the resistance
It's better to have a reason. It doesn't matter if it doesn't

Resistance wire power P = u ^ 2 / R
Error a: after the voltage is halved, P is one fourth of the original
Error B: the current varies with the resistance and voltage
C pair: when the resistance is doubled, the power is halved
Error D: when the resistance is halved, the power is doubled
So choose C