Transformer Multiple Choice Questions
Transformer Multiple Choice Questions 1) A transformer Steps up or down dc voltages Changes ac to dc Steps up or down ac voltages Changes dc to ac Answer: c Explanation: A transformer is an electrical device used to step- up or step-down voltage with constant power. Therefore, a change in voltage level causes a change in current. It means, if the voltage is doubled, the current will be halved. i.e., V = 0.5 I 2) The primary winding of a transformer has a 120 V ac supply. What is the value of secondary voltage if the turn ratio is 10? 120 V 12 V 12000 V 1200 V Answer: d Explanation: Given, N2/N1 = 10 V1 = 120 As we know, V2/V1 = N2/N1 V2/120 = 10 V2 = 120*10 V2 = 1200 V 3) Power transformers are designed to have maximum efficiency at No-load 60 % load 80 % load Full load Answer: d Explanation: Power transformers are usually used for transmission purposes as a step-up device. Power transformers are not directly linked to the consumer side; therefore, it causes very less ...