a) For the R-2R ladder DAC circuit shown in figure2 when digital signal 1010 is applied an output voltage of 18.75 volt was obtained. Calculate 1. The value of Vre; II. Output voltage when input is changed to 1001; and III. IV. Maximum value of analog signal output Resolution. 2R R ww 28 2A 28 28 Figure2 28 ww 28 (3 Marks) (4 Marks) (3 Marks) (3 Marks)