A and B lamps marked with "pz220 40" and "pz220 60" are connected in series in the home circuit (with filament resistance unchanged). After the circuit is connected, the actual power of B lamp is equal to its rated power______ Times. (results retain two significant digits)

A and B lamps marked with "pz220 40" and "pz220 60" are connected in series in the home circuit (with filament resistance unchanged). After the circuit is connected, the actual power of B lamp is equal to its rated power______ Times. (results retain two significant digits)

The resistance of a lamp R1 = u21p1 = (220V) 240W = 1210 Ω, the resistance of B lamp R2 = u22p2 = (220V) 260W ≈ 807 Ω, the circuit current after series connection I = ur1 + R2 = 220v1210 Ω + 807 Ω ≈ 0.1A, the actual power of B lamp P = i2r2 = (0.1A) 2 × 807 Ω = 8.07w, P = 8.07w60w ≈ 0.13