During a 72-ms interval, a change in the current in a primary coil occurs. this change leads to the appearance of a 6.0-ma current in a nearby secondary coil. the secondary coil is part of a circuit in which the resistance is 12 ω. the mutual inductance between the two coils is 3.2 mh. what is the change in the primary current?

so change in primary current is 1.620 A

Explanation:

Given data

current I =6.0-mA = 6 × 10^(-3) A

resistance R = 12 Ω

mutual inductance  M = 3.2 mH = 3.2 × 10^(-3) H

dt = 72-ms = 72 × 10^-(3) s

to find out

change in the primary current

solution

we know that

Electric and magnetic fields in secondary coil  = mutual inductance × change in primary current / dt      1

and we know also that Electric and magnetic fields in secondary coil = resistance × current

so = 6 × 10^(-3) × 12 = 72 × 10^(-3)  volts

so that we say

change in primary current from equation 1

change in primary current  = Electric and magnetic fields in secondary coil × dt / mutual inductance

change in primary current  = 72 × 10^(-3)  ×  72 × 10^(-3) / 3.2 × 10^(-3)

change in primary current  = 1.620

so change in primary current is 1.620 A

nec chapter 5 contains

c. information on special occupancy areas

nec chapter 6 covers

a. special equipment

which of the following rules contain the words shall or shall not and must be adhered to?

b. mandatory rules

which of the following rules identify actions that are allowed but not required and typically cover options or alternative methods?

c. optional rules

which of the following serves as the introduction to the nec and provides an overview of the book?

a. nec article 90

organizations that test products for safety are

c. nrtls

the nec is published by the

a national fire protection association

the nec is divided into

b. 9 chapters

the nec provides informative annexes for

c. informational materials and examples

two terms from nec article 100 that trainees should become familiar with are

b. labeled and listed

explanation:

this is an example of "committed" time.

committed time, as contracted time, takes need over essential and available time since it is seen as profitable work. it alludes to the time allotted to keep up a home and family. at the point when a man is commuting using committed time this individual may feel that the drive is an obligation to family, for example, strolling youngsters to class or driving a mate to work. contracted and committed time clients may feel that their commute could really compare to the commute of important or leisure time clients on the grounds that their commute is profitable work. in this manner, they might be more disposed to pick a mechanized method of movement.