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Figure 6.2 Illustrates the use of transformers in stepping-up and stepping-down operations
6.3 BASIC PRINCIPLE AND CONSTRUCTIONAL DETAILS
Transformers work on the principle of electromagnetic induction. To
understand the principle of working of a transformer, one small experiment
can be performed as explained below. We will need one battery, one single-
way and one two-way switch, two coils, and a PMMC-type dc low-range
center zero voltmeter. The connections are as shown in Fig. 6.3. In Fig. 6.3
(a), when the switch S is turned on and off quickly, the voltmeter neddle will
get deflected. In Fig. 6.3 (b), a two-way switch is used. When the switch is
quickly turned on and off, the current through coil 1 will flow in opposite
directions every time the switch is operated. There will be voltage induced in
the second coil as would be indicated by the deflection of the needle of the
voltmeter in opposite directions.
