hoooney
05-30-2011, 04:42 AM
السلام عليكم
تحية طبة لمن بنى هذا الصرح الطيب..
احضر نفسي لاختبار فيزياء بعد يومين وتوقفت عند بعض الأسئلة *اتمنى منكم مساعدتي في حلها..
A transformer has a coil of 5000 turns. When the output p.d is 12 v.. The input p.d is 240 v r.m.s
A- how many turns are there on the secondary coil?
B- the output from the secondary coil is connected across a 20 *lamp
- what is the r.m.s current in the secondary coil?
- what is the r.m.s current in the primary could ( assume the efficiency of the transformer is 100%)
أنا حليته كالتالي:
A- 12*5000= 240*Ns
= 240 turns
B-*
- 12\20 = 0.6 A
- 240 Ip=12*,6
= 0.03 A
هل أجابتي صحيحة؟
Q2
A step down transformer draws a current of .12 A from the 230 V mains supply. The transformers turns ratio is 1/20. Inefficiency reduces the secondary voltage to 95% of that which is expected
A- calculate the secondary voltage
The secondary voltage coul has a resistance if .50
The transformers load had a resistance of 6.5
Calculate
- the secondary current
- the power output
The efficiency
لم استطع حله*
Q3
A transformer designed to operate a 12 v lamp from a 240v supply has 1200 turns on the primary coil. Assuming that the transformer is 109% efficient. Calculate
- the number of turns on the secondary coil
- the current passing through the primary coil when the 12 v lamp has a current of 2 A flowing throgh it
- Ns*12=1200*240
=240 turns
- I = P/v
P=
12*2= 24w
هل الاجابة صحيحة؟
هل من مساعد؟؟
وشكراً لكم مقدماً
تحية طبة لمن بنى هذا الصرح الطيب..
احضر نفسي لاختبار فيزياء بعد يومين وتوقفت عند بعض الأسئلة *اتمنى منكم مساعدتي في حلها..
A transformer has a coil of 5000 turns. When the output p.d is 12 v.. The input p.d is 240 v r.m.s
A- how many turns are there on the secondary coil?
B- the output from the secondary coil is connected across a 20 *lamp
- what is the r.m.s current in the secondary coil?
- what is the r.m.s current in the primary could ( assume the efficiency of the transformer is 100%)
أنا حليته كالتالي:
A- 12*5000= 240*Ns
= 240 turns
B-*
- 12\20 = 0.6 A
- 240 Ip=12*,6
= 0.03 A
هل أجابتي صحيحة؟
Q2
A step down transformer draws a current of .12 A from the 230 V mains supply. The transformers turns ratio is 1/20. Inefficiency reduces the secondary voltage to 95% of that which is expected
A- calculate the secondary voltage
The secondary voltage coul has a resistance if .50
The transformers load had a resistance of 6.5
Calculate
- the secondary current
- the power output
The efficiency
لم استطع حله*
Q3
A transformer designed to operate a 12 v lamp from a 240v supply has 1200 turns on the primary coil. Assuming that the transformer is 109% efficient. Calculate
- the number of turns on the secondary coil
- the current passing through the primary coil when the 12 v lamp has a current of 2 A flowing throgh it
- Ns*12=1200*240
=240 turns
- I = P/v
P=
12*2= 24w
هل الاجابة صحيحة؟
هل من مساعد؟؟
وشكراً لكم مقدماً