An LR-series circuit has a variable inductor with the inductance defined by L(t) = i(t) = 1 - 1 10 Find the current i(t) if the resistance is 0.2 ohm, the impressed voltage is E(t) = 5, and i(0) = 0. 0 ≤t < 10 t ≥ 10. I 0 ≤ t < 10 t≥ 10

(a) In the figure what value must R have if the current in the circuit is to be 1.1 mA? Take ε1 = 3.0 V, ε2 = 4.2 V, and r1 = r2 = 2.7 Ω. (b) What is the rate at which thermal energy appears in R?

A 100-W (watt) light bulb has resistance R= 146 (ohms) when attached to household current, where voltage varies as V = V, sin(2n fr). where Vo = 110 V. f = 60 Hz. The power supplied to the bulb is P = J/s (joules per second) and the total encrgy expended over a time period [0, 7] (in seconds) is %3! U = P() dt to Compute U if the bulb remains on for 6 hours. (Use decimal notation. Give your answer to one decimal place.) U =

(a) In the figure what value must R have if the current in the circuit is to be 0.84 mA? Take ε1 = 1.9 V, ε2 = 3.4 V, and r1 = r2 = 3.1 Ω. (b) What is the rate at which thermal energy appears in R?