Transformer
Transformer is a device that is used
to raise or lower down the
potential difference of an alternating current.
Function:
The function of a transformer is to increase or decrease the potential difference of an alternating current supply.
A transformer consist of 3 parts, namely
Primary Circuit:The primary circuit is the circuit that connected to the
input energy source. The current, potential difference and coil (winding) in the primary circuit are called the
primary current (Ip),
primary potential difference (Vp) and
primary coil respectively.
Core:The core is the ferromagnetic metal wound by the primary and secondary coil. The function of the core is to transfer the changing magnetic flux from the primary coil to the secondary coil.
Secondary Circuit:The secondary circuit is the circuit that connected to the
output of the transformer. The current, potential difference and coil (winding) in the secondary circuit are called the
secondary current (Is),
secondary potential difference (Vs) and
secondary coil.
Calculation of Potential Difference Change
Calculation of Current Change
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Questions for you :)
1. A transformer has a primary coil of 2000 turns and a secondary of 400 turns.
(a) Is this a step-down or step-up transformer?
(b) If the primary coil is supplied with a voltage of 500V what is the secondary voltage?
(c) If the secondary coil has a voltage of 12V what is the primary voltage?
2. A transformer has a primary coil of 6000 turns and a secondary of 150 turns.
(a) Is this a step-down or step-up transformer?
(b) If the primary coil is supplied with a voltage of 230V what is the secondary voltage?
(c) If the secondary coil has a voltage of 9V what is the primary voltage?
3. A transformer has a primary coil of 400 turns and a secondary of 1600 turns.
(a) Is this a step-down or step-up transformer?
(b) If the primary coil is supplied with a voltage of 30V what is the secondary voltage?
(c) If the secondary coil has a voltage of 800V what is the primary voltage?
4. A transformer has a primary coil of 80 turns and a secondary of 4000 turns.
(a) Is this a step-down or step-up transformer?
(b) If the primary coil is supplied with a voltage of 230V what is the secondary voltage?
(c) If the secondary coil has a voltage of 50kV what is the primary voltage?
5. A transformer has a primary coil of 5000 turns and a primary voltage of 230V.
(a) If the secondary coil has 500 turns what is the secondary voltage?
(b) If the secondary coil has a voltage of 690V what is the number of turns in the secondary coil?
6. A transformer has a secondary coil of 60 turns and a secondary voltage of 10V.
(a) If the primary coil has 500 turns what is the primary voltage?
(b) If the primary coil has a voltage of 2V what is the number of turns in the primary coil?
7. A transformer has a primary coil of 3000 turns and a secondary voltage of 8V.
(a) If the secondary coil has 600 turns what is the primary voltage?
(b) If the primary coil has a voltage of 160V what is the number of turns in the secondary coil?
8. A transformer has a secondary coil of 60 turns and a primary voltage of 230V.
(a) If the primary coil has 1200 turns what is the secondary voltage?
(b) If the secondary coil has a voltage of 46V what is the number of turns in the secondary coil?
Easy? Well those are actually GSCE level questions from United Kingdom...
Moderate? SPM is much more easier than this ...
Hard? Put on more effort, see your teachers :)
