Question

the transformer without power loss carries 4000 turns in the primary and 2000 turns in the secondary. if the primary voltage is 120v and the current is 0.2a. what is the output voltage of transformer​

Answer 1

Given :

No. of turns in primary coil = 4000

No. of turns in secondary coil = 2000

Voltage across primary coil = 120V

Current flow in primary coil = 0.2A

To Find :

Output voltage or voltage across secondary coil.

Solution :

■ The voltage and currents in a transformer are related as

$\bigstar\:\underline{\boxed{\bf{\purple{\dfrac{V_s}{V_p}=\dfrac{I_p}{I_s}=\dfrac{N_s}{N_p}=k}}}}$

Vs : voltage across secondary coil

Vp : voltage across primary coil

Is : current flow in secondary coil

Ip : current flow in primary coil

Ns : no. of furns in secondary coil

Np : no. of turns in primary coil

k : transformation ratio

By substituting the given values;

$:\implies\sf\:\dfrac{V_s}{V_p}=\dfrac{N_s}{N_p}$

$:\implies\sf\:\dfrac{V_s}{120}=\dfrac{2000}{4000}$

$:\implies\sf\:\dfrac{V_s}{120}=0.5$

$:\implies\:\underline{\boxed{\bf{\orange{V_s=60\:volts}}}}$

★ Remember :

⇒ For a step up transformer,

• k > 1

⇒ For a step down transformer,

• k < 1

⇒ For an ideal transformer

• Power in primary coil = Power in secondary coil