Measurement of Capacitance by Schering Bridge 
A schering Bridge consists of the following: Arm ab-unknown capacitance with internal resistance which has to be measured. Arm ad- known capacitor value is 1.5uF. Arm bc- non inductive resistance value is 130 Ω. Arm dc-a known capacitor value is 3uF with known reactive resistance 260 Ω.Calculate the values of C1 and it's internal resistance R1.
Which instrument measures the total quantity of electricity delivered in a particular time?