1. A voltage divider circuit is to be constructed to obtain an output voltage 3 V (ptp) from an a.c. supply of 12 V (ptp). If the value of one of the available resistor pair is 6 kΩ, then the value of the other resistor with the output voltage across it is; 1 kΩ 2 kΩ 3 kΩ 4 kΩ None of the above so i know the formular is 12 x(R2/R1+R2) but what do i do if i only have the value for 1 Resistor. MY answer was 2. but i did it with an unorthodox way. is there a formula i can use to find the value of the hidden resistor. and is that unknown resistor R2 or R1?