Answer:
(a)  
  and
 and  
 
(b)  lagging
 lagging
Explanation:
Given Data:





(a) Find the required kVAR rating of a capacitor
 °
°
 °
°
The required compensation reactive power can be found by


 
 
The corresponding capacitor value can be found by


 
 
(b) calculate the resultant supply power factor
First convert the hp into kW
 
 
Find the electrical power (real power) of the motor

where  is the efficiency of the motor
 is the efficiency of the motor
 
 
The current in the motor is

The pf of motor is 0.85 Leading
Note that  represents the angle in complex notation (polar form)
 represents the angle in complex notation (polar form)


 
 
Now find the Load current 
pf of load is 0.75 lagging (notice the minus sign)


 
 
Now the supply current is the current flowing in the load plus the current flowing in the motor


 
 
or in polar form
 °
°
Which means that the supply current lags the supply voltage by 24.78
therefore, the supply power factor is
 lagging
 lagging
Which makes sense because original power factor was 0.75 then we installed synchronous motor which resulted in improved power factor of 0.90