Deck 14: Transformer Basics

Question 1

Practical estimates of primary or secondary currents are made by assuming that transformers are ____________________% efficient.

Answer 1

100
one hundred

Question 2

The primary winding of a transformer has 100 turns, and the secondary has 400 turns. An EMF of 120 volts is applied to the primary. What is the voltage at the secondary?

Answer 2

The voltage at the secondary is 480 volts.

Question 3

The ratio of turns, primary to secondary, is usually listed in the schematic diagram of a transformer.

Answer 3

False

Question 4

What does the term "permeability" describe?

Question 5

A transformer consists of two or more conductor ____________________ placed on the same iron core magnetic path.

Question 6

Explain the difference between a step-up transformer and a step-down transformer.

Question 7

The current in the secondary controls the current in the primary.

Question 8

The current ratio in a transformer is the inverse of the ratio for voltage transformation.

Question 9

How does a core loss occur?

Question 10

According to ____________________'s law, a voltage is induced in the coil whenever the coil current is increased or decreased.

Question 11

Induction is illustrated by arranging two loops of wire.

Question 12

The core transformer is a more efficient type of core construction than the shell.

Question 13

A counter ____________________, called self-inductance, is induced in the primary winding and opposes the impressed voltage.

Question 14

The____________________, or H, core is also called the modified shell type.

Question 15

Define the efficiency of all machinery.