5. A convex mirror forms an image of half the size of the object. When it is moved 15 cm away from the object, the size of the image becomes
2.
times that of the object. Find the focal length of mirror Ans: -30 cm

In the circuit, the switch s has been open for a long time and r = 125 kohm. it is then suddenly closed. (a) determine the time constant before the switch is closed. s (b) determine the time constant after the switch is closed. _ s (c) let the switch be closed at t = 0. find the current in the switch as a function of time. (use t for time. express your answer in milliamps and seconds.) i(t) =_