Question

How much current is drawn by the primary coil of a transformer which steps down 220 V to 22 V to operate a device having a current 0.1 A?

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Answer 1

Correct Question :

• How much current is drawn by the primary coil of a transformer which steps down 220 V to 22 V to operate a device having an impedance of 220 Ω?

Given

• V of primary coil = 220 V
• V in secondary coil = 22 V
• Impedance = 220Ω

To Find

• Current drawn

Solution

☯ P = V²/R

• We shall use this to find the power that's developed in the secondary coil

☯ P = VI

• This can be used to find the current flow, and hence our Answer!!

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✭ According to the Question :

→ P = V²/R

→ P = 22²/220

→ P = 484/220

→ P = 2.2 W

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→ P = VI

→ 2.2 = 220 × I

→ 2.2/220 = I

→ Current = 0.01 A

Answer 2

Answer:

Given :-

• The primary coil of a transformer which steps down 220 V to 22 V.

To Find :-

• How much current drawn.

Formula Used :-

❶ To find electric power,

★ P = V² ÷ R ★

where,

• P = Electric power
• V = Voltage
• R = Resistance

❷ To find current,

✯ I = P ÷ V ✯

where,

• I = Current
• P = Electric power
• V = Voltage

Solution :-

❶ First we have to find the electric power,

Given :

• V = 22 V
• R = 220 V

According to the question by using the formula we get,

⇒ P = (22)² ÷ 220

⇒ P = 484 ÷ 220

➠ P = 2.2 W

❷ Now we have to find the current,

Given :

• P = 2.2 W
• V = 220 V

According to the question by using the formula we get,

↦ I = 2.2 ÷ 220

➦ I = 0.01 A

∴ The current drawn on the coil is 0.01 A .