A. The current through a lamp connected across 154 V is 1.25 A when the lamp is on. What is the lamp’s resistance when it is on (and hot)? b. When the lamp is COLD, its resistance is one forth as large as it is when the lamp is hot. What is its COLD resistance?

c. Then what would the current through the lamp be just after it is turned on, when it is still cold? (Still connected to a potential difference of 154 V.)

The metal wire in an incandescent lightbulb glows when the light is switched on and stops glowing when it is switched off. this simple process iswhich kind of a change? a.a physical changeb. a chemical changec. a nuclear changed. an ionic change

The membrane surrounding a living cell consists of an inner and an outer wall that are separated by a small space. assume that the membrane acts like a parallel plate capacitor in which the effective charge density on the inner and outer walls has a magnitude of 7.0 × 10-6 c/m2. (a) what is the magnitude of the electric field within the cell membrane? (b) find the magnitude of the electric force that would be exerted on a potassium ion (k+; charge = +e) placed inside the membrane.

Efficiency is the ratio of to for a system a)power in to power in b)power in to power out c) power out to power out d) power out to power in