1.Transformers are normally used to step up or step down alternating voltage or current. May dc also be used to step up or step down voltage or current? Motivate your answer?2.The supply voltage of a step down transformer is 240 volts and the winding ratio is 4,8 : 1. If there are 2000 turns on the primary winding calculate:2.1) The number of turns on the secondary2.2) The primary current when the secondary current is 15 A3. Calculate the secondary voltage of a transformer with supply voltage of 415 volts, the winding ration is 36 : 14.Can an Autotransformer be used to step up pulsating dc current? Motivate your answer.
A transformer works on the precept of induction. The essential coil of the transformer induces a voltage in secondary coil propotional voltage utilized to it. For this to happen there must a various magnetic flux produced with the aid of the primary coil. Due to the fact that U deliver a DC voltage, magnetic flux produced through the pri coil is zero on account that that the frequency of a DC is zero (be aware: The magnetic flux produced is straight propotinal to the applied frequency) as a result a DC voltage can not be stepped up or down but a pulsating DC will also be tried.
1.strictly NO.DC cannot be used at all to step up and step down using transformer if you read the working of transformer,it works on the principle of electromagnetic induction. i.e. it depends on change of flux with time. it can only happen in ac voltages not in dc ones because in dc the volatge is fixed but in ac it changes with time and flux and current are directly proportional. 2. 2.1)it is step down transformer. so number of turns in primaryno. of turns in secondary NpNs 4.8/12000/Ns Ns2000/4.8 Ns416.6777 but no of turns needs to be an integer so Ns417 (round off) 2.2)Ip/IsNs/Np IpIs*Ns/Np 15*2000/417 71.94A 3) 415/Vs36/1 Vs11.53V 4) Yes. such transfomers are called pulse transformers.
