21. You wish to build an adjustable delay line using electrical switches as shown in the diagram below. L +1 L+1 I L+1 Its purpose is to adjust the delay of an electrical signal through the delay line by switching different amounts of delay into the signal path. The delay line should use the minimum amount of switches. The delay line should have a minimal delay of Lmin and a maximal delay of Lmar < Lmin +AL. We refer to AL as the delay range. The delay should be adjustable in increments of 6L so that the line can achieve an evenly spaced set of delays between Lmin and Lmar with a resolution of 8L. For all segments in the line you have to determine a common, small delay / which is active when its switch is in the lower position. You further have to determine a larger, individual delay of L +1>1 for each seg- ment which is active when its switch is in the upper position. For a line with n segments to satisfy the demands on the minimum number of switches, minimum delay Lmin, delay range AL and delay resolution 8 L: (a) Find a value for I in terms of Lmin and n. (b) Find the delays of each segment L, in terms of L. (c) Find the minimum necessary n in terms of AL and L [1] [3] [3]