Question

if n1 and n2 are number of turns in primary and secondary coil of a step up transformer then​

Answer 1

Given :

No. of turns in primary coil = n₁

No. of turns in secondary coil = n₂

To Find :

Relation between n₁ and n₂.

Solution :

The voltage and currents in a transformer are related as

$\dag\:\underline{\boxed{\bf{\orange{\dfrac{V_2}{V_1}=\dfrac{I_1}{I_2}=\dfrac{n_2}{n_1}=k}}}}$

⟩ For step-up transformer, k > 1

⟩ For step-down transformer, k < 1

$\sf:\implies\:k>1$

$\sf:\implies\:\dfrac{n_2}{n_1}>1$

$:\implies\:\underline{\boxed{\bf{\red{n_2>n_1}}}}$

Knowledge BoosteR :

• A step-up transformer changes a low voltage into a high voltage. This does not violate the law of conservation of energy. The current decreases by the same proportion. When voltage increaeses n times, the current reduces to 1/n times.
• In the same way a step-down transformer changes a high voltage into low voltage. When voltage decreases (1/n) times, the current increase to n times.
• A transformer is essentially an a.c. device. It cannot work on d.c. It changes alternating voltages/currents. It does not affect the frequency of a.c.