A high-intensity desk lamp is rated at 45 W but requires only 12 V. It contains a transformer that converts 120-V household voltage, (a) Is the transformer step-up or stepdown? (b) What is the current in the secondary coil when the lamp is on? (c) What is the current in the primary coil? (cf) What is the resistance of the bulb when on?
Step 1 of 4
The primary voltage
The secondary voltage
The transformer converts 120V to 12V. Primary voltage is bigger than secondary voltage so it is step-down transformer.