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If the ratio of power to resistance is 1:9 and the ratio of resistance is 1:4, then the ratio of current passing through them is?
2: Three is right
Just solve the following equations
I1^2R1：I2^2R2=1：9
R1: R2 = 1:4 to simplify the formula: R2 = 4r1 into the above formula
I1 ^ 2r1: I2 ^ 2 * 4r1 = 1:9 after simplification I1 ^ 2:4i2 ^ 2 = 1:9
Further simplification: I1 ^ 2: I2 ^ 2 = 4:9 square root: I1: I2 = 2:3
^2 is the square
Don't say you can't solve equations
A and B two electrical appliances, in which the ratio of electric power is 1:4, the ratio of resistance value is 1:9, what is the ratio of their current
The current ratio is 3 / 2
Whether in series or parallel, it is proved that the total electric work in the circuit is equal to the sum of the partial electric work
Electric power (P) = voltage (U) x current (I);
Note: only when the voltage and current are in phase;
P = U x I ；
P = U x （i1 + i2 +...+ in）= U x i1 + U x i2 +...+ U x in = P1+P2+.+Pn；------- (1)
P = （u1 + u2 +.+ un）x I = u1 x I + u2 x I +.+ un x I = P1+P2+.+Pn；------- (2)
The first formula is parallel connection, the total current is equal to the current of each circuit;
The second formula is the case of series connection, where the total voltage is equal to the sum of the voltages of the series connected devices;
The resistance of the device can also be used to calculate u x i = I ^ 2 / R;
I hope you can understand the concept of energy conservation through learning. If you can't fully understand it, just memorize it
Is the total power in a series circuit equal to the sum of the powers? Is it parallel?
In a series circuit, the total power is equal to the sum of the powers
Because of the total power
P=UI=（U1+U2+U3+…… )I=U1I+U2I+u3I+…… =P1+P2+P3+……
In parallel circuit, the total power is equal to the sum of each power
Because the total power P = UI = u (I1 + I2 + I3 +...) )=UI1+UI2+UI3+…… =P1+P2+P3+……
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