After a 110V, 100W light bulb is connected in series with a 100V, 40W light bulb, it can be connected to the 220V circuit to judge whether the problem is right or wrong

After a 110V, 100W light bulb is connected in series with a 100V, 40W light bulb, it can be connected to the 220V circuit to judge whether the problem is right or wrong

100W resistance R1 = U2 / P = (110V) 2 / 100W = 121 Ω
The resistance of 40W R2 = U2 / P = (100V) 2 / 40W = 250 Ω
After they are connected in series, the voltage ratio is about U1: U2 = R1: R2 = 1:2
The voltage at both ends of 40W lamp is about 2 / 3 × 220V = 147v, which is far beyond the rated voltage

Can two bulbs with rated values of 110V, 60W and 110V, 40W be connected in series to work on the power supply of 220V? Why?

No
Rated current of R1: I1 = P1 / U1 = 0.55a
R2 rated current: I2 = P2 / U2 = 0.36A
R1 = u square / P = 201 Ω
R2 = u square / P = 302 Ω
After series connection: r = R1 + R2 = 503 Ω
I = u / r = 220 / 503 = 0.44 a, more than 0.36 a, so 40W bulb burned out, so it can not be used in series