(20 14? A model in Sihong county) Xiaoming designed an "infusion alarm" in the school's scientific and technological activities (its schematic diagram is shown in the picture), which can be used as a

(20 14? A model in Sihong county) Xiaoming designed an "infusion alarm" in the school's scientific and technological activities (its schematic diagram is shown in the picture), which can be used as a whole bottle of liquid medicine. (1) Liquid volume:

v=500mL=500× 10-6m3，

Quality of liquid medicine:

m =ρv = 1.04× 103kg/m3×500× 10-6 m3 = 0.52kg，

Gravity of liquid medicine:

G=mg=0.52kg× 10N/kg=5.2N。

When the pointer is B, the pointer of the spring dynamometer is the total weight of the bottle and the liquid medicine; When the pointer is in position A, the contact AB contacts, and the electric bell rings to indicate that the medicine is used up. At this time, the spring dynamometer indicates the gravity of the bottle (regardless of the quality of the bottle);

It can be seen that the difference between the calibration values of A and B is the specific gravity of 5.2N; ;

(2) As can be seen from the figure, the bulb is connected in series with the resistor, that is, the current is equal.

∫P = UI，

∴ current in the circuit:

I=I lamp =P lamp U lamp =3W6V=0.5A,

Therefore, the total power consumed by the circuit:

p = UI = 10v×0.5A = 5W；

(3)∵ bulb series resistance, U lamp =6V.

∴UR= 10V-6V=4V，

IR=I lamp =0.5A,

∫R = UI

∴ Resistance:

R = URIR = 4V0.5A = 8Ω。

Answer: (1) The difference between the scale values of A and B is 5.2n；;

(2) The total power consumed by the circuit is 5W;

(3) The resistance of the resistor is 8 ohms.