Efficiency and Testing of DC Machines

Hopkinson’s test is also called regenerative test due to

The efficiency in the swineburne’s test can be found.

The main concern before doing hopkinson’s test for finding efficiency is

______ test is used for determining the efficiency of a traction motor

In the Hopkinson’s test on two DC machines. Machine A has field current of 1.4A and B has field current of 1.3A. Which machine acts as generator?

The quantities needed to complete retardation test are/is

Similarity between Hopkinonson’s and field’s test is that

The possible assumption is/are made while doing swineburne’s test
(i) mechanical loss constant
(ii) Armature reaction neglected
(iii) Increases in flux

A dc motor is connected in the short-shunt configuration, but the series and the shunt windings get interchanged by mistake and the motor is connected to the rated voltage,

Retardation test on DC shunt motor is used for finding _______

Mark the possible causes of overheating of commutator in a DC machine

In the hopkinson’s test on two DC machines. Machine A has field current of 1.4A and B has field current of 1.3A. Which machine acts as motor?

If the field current and armature current are reversed, then

The most appropriate relation to find efficiency of the generator

Swineburne’s test is applicable to those machines in which flux is practically _____