PHYS 1008 2022W Last Name (please print) Test #2 Section L2 Thurs P.M. First Name (please print) Duration: 45 min Student # (please print) TA Name (please print) (8) 1. Capacitors are used in many applications where you need to supply a short burst of energy. A 68 MF capacitor in an electronic ash lamp supplies a total of 41 J of energy. (a) To what potential difference was the capacitor initially charged? ( 3 marks) (b) If the capacitor's plate separation was d = 0.50 mm, then what was the electric eld within the capacitor? (2 marks) (c) What was the energy density (u : (1 / 2)0E2) within the capacitor? Assume k = 1. (3 marks) (8) 2. In the single loop circuit shown below, R : 10.0 k9 and C : 50.0 ,aF. Initially, the switch is open and the capacitor is uncharged. Then, at time t : 0 the switch is closed. The emf source provides a potential of 5 = 36.0 volts. (a) Determine the time constant 7' for the capacitor to charge. (2 marks) (b) After a long time, what is the potential difference across the capac- itor? (2 marks) (c) How much time is needed for the charge on the capacitor to grow to 75.0% of its nal value? (4 marks)