which of the following statements are true regarding transformers? choose all correct answers. group of answer choices in a transformer, if the primary coil contains more loops than the secondary coil, then it is a step-up transformer. in an ideal transformer, the power input is less than the power output. in a transformer, if the secondary coil contains more loops than the primary coil, then it is a step-up transformer. a transformer is used to increase or decrease a dc voltage. a transformer converts mechanical energy into electrical energy. a transformer is used to increase or decrease an ac voltage.