A substance undergoing a physical change will still weigh the same even after the change. This is in accordance to the law of conservation of mass which states that mass is neither created nor destroyed. so an 8 g substance remains of the same weight even after undergoing a physical change.
Answer:
Turns of the primary coil: 500
Current in the primary coil: Ip= 0.01168A
Explanation:
Considering an ideal transformer I can propose the following equations:
Vp×Ip=Vs×Is
Vp= primary voltaje
Ip= primary current
Vs= secondary voltaje
Is= secondary current
Np×Vs=Ns×Vp
Np= turns of primary coil
Ns= turns of secondary coil
From these equations I can clear the number of turns of the primary coil:
Np= (Ns×Vp)/Vp = (20×120V)/4.8V = 500 turns
To determine the current in the secondary coil I use the following equation:
Is= (1.4W)/4.8V = 0.292A
Therefore I can determine the current in the primary coil with the following equation:
Ip= (Vs×Is)/Vp = (4.8V×0.292A)/120V = 0.01168A
