Question

Exercise 3. Explain the difference in the meaning of these expressions by using them
in sentences of your own:
1. to back out, to back up
2. to come off, to come across
3. to hold on, to hold back
4. to let down, to let off
plz help me​

Answer 1

Answer:

A rectifier is a device that converts an oscillating two-directional alternating current (AC) into a single-directional direct current (DC). Rectifiers can take a wide variety of physical forms, from vacuum tube diodes and crystal radio receivers to modern silicon-based designs.

Explanation: