Ideal Transformer

Question

An ideal step-down transformer has 1000 turns in its primary winding and 200 turns in its secondary winding, and its primary is connected to a 220 volt AC supply. What voltage appears across the secondary terminals?

RankGuru · Accepted Answer

As given in NCERT Class 12, Chapter 7 (Alternating Current), an ideal transformer conserves power and relates primary and secondary voltages to turns through $\frac{V_s}{V_p} = \frac{N_s}{N_p}$, because the same flux links every turn of both windings. Rearranging: $V_s = V_p 	imes \frac{N_s}{N_p} = 220 	imes \frac{200}{1000} = 220 	imes 0.2 = 44\ 	ext{V}$. The option 1100 V inverts the ratio, treating the device as a step-up transformer. The option 22 V uses a turns ratio of one-tenth instead of one-fifth. The option 88 V mistakenly uses a ratio of 0.4. A plausibility check confirms that for a step-down transformer the secondary voltage must be smaller than the primary, and 44 V is indeed below 220 V, matching the turns ratio of 1:5. Since the transformer is ideal, the secondary current correspondingly rises to keep the power product $V I$ unchanged between the two sides.

Ideal Transformer

Select the correct option:

🔒 Solution Hidden from View

More electromagnetic induction and alternating currents Practice Questions

In a purely capacitive alternating current circuit connected to an oscillating source, what is the a...

An alternating current circuit draws an rms current of 5 amperes from a 200 volt rms supply, and the...

When an alternating voltage is applied across a pure resistor, what is the phase relationship betwee...

A current of 4 amperes flows steadily through a coil having a self-inductance of 0.5 henry. How much...

A rectangular armature coil of an AC generator has 100 turns and area 0.05 square metres, rotating a...

A series circuit contains a resistor of 30 ohm and an inductor whose inductive reactance is 40 ohm, ...

In the design of transformer cores and electromagnetic braking systems, why are the metallic cores c...

A series LCR circuit at resonance has an inductive reactance of 500 ohm and a resistance of 25 ohm. ...

A charged capacitor of 2 microfarads is connected across an ideal inductor of 8 millihenry to form a...

The current flowing through a coil of self-inductance 0.6 henry is reduced steadily from 10 amperes ...

In an AC circuit, a capacitor of capacitance 25 microfarads is connected to a source whose frequency...

A series LCR circuit contains an inductor of 2 henry and a capacitor of 8 microfarads along with a r...

About This Question

Solution