THE DESIGN OF DIRECT-CURRENT 
1. 
9. 
DYNAMOS AND MOTORS. 
In what form is a problem of generator design. usually 
given? 
Give the formula for the current strength of a generator if 
its capacity and voltage are known. 
State the form in which a problem of motor calculation is 
usually given. 
Give the formula for the output of a generator which corre- 
sponds to a motor of given horse-power. 
Express the counter E. M.. F. of a motor in terms of the 
supply voltage. 
By what formula can the current strength of a motor be 
found, if its output, its voltage, and its electrical efficiency 
are given? 
Find the electrical power equivalent to a motor output of 15 
_ horse-power. 
What is the average counter E. M. F. of a 2 H. P. motor 
designed to operate on a 110-volt circuit? 
Compute the full-load current of a 50 H. P. motor run from 
a 250-volt circuit. * - 
