A laboratory set-up to be used for power frequency withstand tests up to 1200kV is shown in the figure below. The main items of the testing set-up are: 1. Testing Transformer Cascade-consisting of three identical transformer units of the insulating cylinder type. The cascade has the following rating: 1200kV, 0.8A, 1500kVA and 25% impedance voltage. The primary winding of the first stage is supplied from a 12KV, 50Hz regulated power supply. The inherent stray capacitance of the transformer windings plus the capacitances of the top electrode and connecting cylinders add to about 600pF. 2. The Capacitive Voltage Divider System - consisting of a screened high voltage condenser C1 = 100pF. a low voltage arm C2. The voltage across C2 is measured by means of DVM having a maximum range of 1000V (V2). Cascade Transformer Capacitive Voltage Divider Test Object a) Determine the maximum capacitance (in pF) of a test object which can be tested at 1200KV. Please take into consideration the effect of stray capacitance and the capacitance of the capacitive divider. [10 marks] b) Calculate the capacitance C2 of the low voltage arm of the C-divider (in uF) required so that the full- scale reading of the voltmeter of 1000V corresponds to the maximum voltage of the transformer. [5 marks] c) A test object of 500pF capacitance is connected in the circuit and the voltage applied to the test object is 1000kV. Determine the which would be measured on the input to the primary winding of the first corresponding voltage (in kV) stage of the cascade. [10 marks]