## What are the characteristic curves are drawn in DC generator characteristics?

An internal characteristic curve shows the relation between the on-load generated emf (Eg) and the armature current (Ia). The on-load generated emf Eg is always less than E0 due to the armature reaction.

## What is OCC curve?

The open circuit characteristics (O.C.C) or magnetization characteristics is the curve that shows the relationship between the generated EMF at no-load (E0) and the field current (If) at constant speed. It is also known as no-load saturation curve.

**Which of the following is the operating characteristics of DC generator?**

Identify the armature characteristic of the dc generator. Explanation: At low values of the armature conductor, the increase in the field current is very small to provide IaRa drop. At large armature current,field current increases sharply to compensate for the voltage drop caused by armature reaction.

### What is on load characteristic of a DC generator?

The external characteristics or load characteristics is the plot between the terminal voltage (V) and load current (IL). Since, the terminal voltage is less than the generated voltage due to armature and series field copper losses.

### What are the different characteristics and uses of each DC generator and motor?

Difference between DC Motor and DC Generator

Characteristics | DC Motor | DC Generator |
---|---|---|

Operation | If apply more power, it rotates its shaft faster which is contingent upon motor’s rating | It produces fixed voltage at a rated rpm (revolution per minute) |

Types | Shunt and compound wound | Shunt, compound, and series wound |

**What is OCC and SCC curve?**

Open circuit characteristic (OCC) and Short Circuit Characteristics (SCC) of a Synchronous generator. With the armature terminals open, Ia=0, so Eg = Vt It is thus possible to construct a plot of Eg or Vt vs If graph.

#### What is the difference between OCC external and internal characteristics curve of DC generator?

An external characteristic curve shows the relation between terminal voltage (V) and the load current (IL). Terminal voltage V is less than the generated emf Eg due to voltage drop in the armature circuit. Therefore, external characteristic curve lies below the internal characteristic curve.

#### What is the nature of characteristics of DC shunt generator?

AC curve is showing the external characteristic of the shunt wound DC generators. It is showing the variation of terminal voltage with the load current. Ohmic drop due to armature resistance gives lesser terminal voltage the generated voltage. That is why the curve lies below the internal characteristic curve.

**What are the characteristics of a DC motor?**

Generally, three characteristic curves are considered important for DC motors which are, (i) Torque vs. armature current, (ii) Speed vs. armature current and (iii) Speed vs. torque.

## Why SCC is straight line and not curve?

SCC depicts copper loss, which is purely based on resistance, hence the graph is linear. OCC is linear upto saturation point, as it depicts core loss, which is based partly on induction/magnetisation. Hence it has a curve above saturation point.