2. Find the IN and RN of the circuit shown below as seen from the terminals A and B. 10V 212 63 72 www A www ~m/i/1 GA 342 12V 52 - B

Number 2 A piece of beef steak 7 cm thick will be frozen in the freezer room -30°C. This product has a moisture content of 73%, a density of 970 kg/m³, and a thermal conductivity (frozen) of 1.1 W/(m²K). Estimate the freezing time. using the Plank equation. This product has an initial freezing temperature of -1.75°C, and the movement of air in the freezing room gives a convective heat transfer coefficient of 15 W/(m²K). t f = answer in hour

why is the ans 7.8

Problem 11: Part (a)  At time t = 0 the switch is closed and current flows through the circuit. The current increases with time and eventually reaches a steady state value of imax. Calculate the maximum current imax in units of milliamps.  imax = ______ Part (b)  Write an equation that relates the current as a function of time i(t) to the maximum current, imax. Express the equation in terms of imax and α, where α = -t/τ.  i(t) = ______ Part (c)  Determine the time, in seconds, at which the current has a value of i(t50) = 50% of imax.  t50 = ______