How would the illustration look if it were showing a step-down transformer?

Describe how turning off the electric current in an industrial electromagnet affects its magnetic field.

Why do some appliances have step-down transformers built in?

A preheater involves the use of condensing steam at $100^{\circ} \mathrm{C}$ on the inside of a bank of tubes to heat air that enters at 1 atm and $25^{\circ} \mathrm{C}$. The air moves at 5 m/s in cross flow over the tubes. Each tube is 1 m long and has an outside diameter of 10 mm. The bank consists of 196 tubes in a square, aligned array for which $S_{T}=S_{L}=15 \mathrm{mm}$. What is the total rate of heat transfer to the air? What is the pressure drop associated with the airflow?

A step-down transformer is used for recharging the batteries of portable devices. The turns ratio $N_2/N_1$ for a particular transformer used in a CD player is 1:13. When used with 120-V (rms) household service, the transformer draws an rms current of 250 mA. Find the rms output voltage of the transformer

A model-train transformer plugs into $120-\mathrm{V}$ ac and draws $0.35 \mathrm{~A}$ while supplying $7.5 \mathrm{~A}$ to the train. (b) Is the transformer step-up or step-down?

A $220 / 20-\mathrm{V}$ transformer has 50 turns on its low-voltage side. Calculate: a. The number of turns on its high side. b. The turns ratio $\alpha$ when it is used as a step-down transformer. c. The turns ratio $\alpha$ when it is used as a step-up transformer.

Electric doorbells found in many homes require 10.0 V to operate. To obtain this voltage from the standard 120-V supply, a transformer is used. Is a step-up or a step-down transformer needed, and what is its turns ratio

$$N _ { s } / N _ { p } ?$$

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. Is the transformer step-up or step-down?

What is the difference between a step-up transformer and a step-down transformer?

A step-down transformer is used for recharging the batteries of portable devices such as tape players. The turns ratio inside the transformer is $13: 1$ and it is used with $120-\mathrm{V}$ (rms) household service. If a particular ideal transformer draws $0.350 \mathrm{~A}$ from the house outlet, what are (a) the voltage and (b) the current supplied to a tape player from the transformer? (c) How much power is delivered?

Consider a very long rectangular fin attached to a flat surface such that the temperature at the end of the fin is essentially that of the surrounding air, i.e., $20^{\circ} \mathrm{C}.$ Its width is 5.0 cm; thickness is 1.0 mm; thermal conductivity is $200 \mathrm{W} / \mathrm{m} \cdot \mathrm{K};$ and base temperature is $40^{\circ} \mathrm{C}.$ The heat transfer coefficient is $20 \mathrm{W} / \mathrm{m}^{2} \cdot \mathrm{K}.$ Estimate the fin temperature at a distance of 5.0 cm from the base and the rate of heat loss from the entire fin.

a. What does a transformer do? b. Interpreting Diagrams . What is the difference between a step-up transformer and a step-down transformer? c. Why do some appliances have step-down transformers built into them?

Can an efficient transformer step up energy? Defend your answer.