1)Explain how a diode could be used to convert a. c. to d. c., and suggest one disadvantage of this.

2) Some energy is always transferred to the surroundings when a current flows through a wire.

a) How is this energy transferred?

b) Is this energy always wasted energy? Explain your answer.

3) You can induce an electric current in a wire by moving a magnet relative to the coil.

A) Describe two different ways in which you can increase the size of the induced current.

B) Describe how you can reverse the direction of the induced current.

At a certain instant after jumping from the airplane a, a skydiver b is in the position shown and has reached a terminal (constant) speed vb = 52 m/s. the airplane has the same constant speed va = 52 m/s, and after a period of level flight is just beginning to follow the circular path shown of radius ρa = 2330 m. (a) determine the velocity and acceleration of the airplane relative to the skydiver. (b) determine the time rate of change of the speed vr of the airplane and the radius of curvature ρr of its path, both as observed by the nonrotating skydiver.

Amachinist turns the power on to a grinding wheel, at rest, at time t = 0 s. the wheel accelerates uniformly for 10 s and reaches the operating angular velocity of 96 rad/s. the wheel is run at that angular velocity for 40 s and then power is shut off. the wheel slows down uniformly at 1.5 rad/s2 until the wheel stops. in this situation, the time interval of deceleration is closest to:

What sort of waves exhibit the doppler effect?