[填空题]
An ordinary flashlight uses two D-cell 1.5-V bat(p + de:;silkuteries conq 4mmv7w l:bj2nected in series as in Fig. 18–4b (Fig. 18–m:qvl w7m4jb 236). The bulb draws 450 mA when turned on.
(a) Calculate the resistance of the bulb and the power dissipated.
$\approx$ $\Omega$(retain one decimal places)
W
(b) By what factor would the power increase if four D-cells in series were used with the same bulb? (Neglect heating effects of the filament.) Why shouldn’t you try this?
