DCMT(DC Machines and Transformers), 2-1 SEMESTER Previous year Question paper, R23 regulation

 

DCMT 2-1 SEMESTER Previous Year Question Paper R23 Regulation 

  Hi, here we have the DCMT 2-1 SEMESTER PYQ (Previous Year Question Paper). The 2-1 SEMESTER exam mainly focuses on five units:

➡️ DC Machines
➡️ Speed Control and Testing of DC Machines
➡️ Single-phase Transformers
➡️ Testing of Transformers
➡️ Three-Phase Transformers

Now, let's first look at the concepts covered in each unit.

UNIT – I: DC Machines

Construction and principle of operation of DC machines – EMF equation for generator - Excitation techniques – characteristics of DC generators –applications of DC Generators, Back-emf and torque equations of DC motor – Armature reaction and commutation.

UNIT – II: Speed Control and Testing of DC Machines

Characteristics of DC motors – losses and efficiency – applications of DC motors. Necessity of a starter – starting by 3-point and 4-point starters – speed control by armature voltage and field current control – testing of DC machines – brake test, Swinburne’s test –Hopkinson’s test–Field Test.

UNIT – III: Single-phase Transformers
Introduction to single-phase Transformers (Construction and principle of operation)–emf equation –

operation on no-load and on load –lagging, leading and unity power factors loads –phasor diagrams–

equivalent circuit –regulation – losses and efficiency – effect of variation of frequency and supply

voltage on losses – all day efficiency.
UNIT –IV: Testing of Transformers
Open Circuit and Short Circuit tests – Sumpner’s test – separation of losses–– Parallel operation with

equal and unequal voltage ratios– auto transformer – equivalent circuit – comparison with two winding

transformers.
UNIT – V: Three-Phase Transformers:Polyphase connections- Y/Y, Y/Δ, Δ/Y, Δ/Δ, open Δ and Vector groups – third harmonics in phase

voltages– Parallel operation–three winding transformers- transients in switching –off load and on load

tap changers–Scott connection.

 📜Mid-1 Paper Overview

Part-A (20 Marks):

It contains 10 short questions, each carrying 2 marks.

Part-B (50 Marks):

It contains 5 sets of questions. Each set has 4 questions, out of which 2 questions must be answered. Each set carries 10 marks.