please shear what is the ratio of magnetizing current of a transformer against of full load current of transformer.

Ghulam,

Your question requires clarification. In what context are you interested; initial energization, no load loss, leakage current, etc.

Alan

The magnetic inrush current is normally 12X the full load current at 0.1 sec and 25X at 0.01 sec. This is used in fuse co-ordination studies.

Steady state magnetizing current of a transformer is always less than 2% of its full load nominal current at its rated voltage and frequency.and at nominal tap position of Off Circuit Tap Switch ( OCTS) or On Load Tap Changer (OLTC) as the case may be.
For ratings less than 500 kVA it can be as high as 2.5 % .

It depends on the size and type of transformer. No-load magnetising current as % of full load current with today's technology is as below:
Distribution Transformers :
Stacked core – 3% of Full Load current
Wound core – 2 % of FL current (Actual values: 0.5-1.5 % with ZDKH –M4 material at 1.7 T, Power Factor -0.8-0.9)
Power Transformers:
20-315 MVA -0.1 % ( 20 MVA) to 0.05 % (315 MVA), Power factor -0.5-0.9
500 MVA single phase 765/400 kV Auto-Transformer – Current=0.03 % PF=0.41