[填空题]
A flash lightbulb rated at 2.5 W and ;oyels9 a4ukp a vkgry7;5e90 3.0 V is operat9fp+t txfyyy:,p0 s t/ed by a 9.0-V battery. To light the bulb at its rated voltage and power, a resistor R is connected in series as shown in (Fig. Below). What value should the resistor have,t:p yt/ y09xpsyt+ff? $\Omega$
