mememe11
New Member
- Joined
- Mar 20, 2009
- Messages
- 9
- Gender
- Female
- HSC
- 2010
transformers have conservation of energy, hence V_1I_1=V_2I_2 but how can u get more voltage but less current; assuming ohmic resistors, by ohm's law if resistance is the same (as my teachers tell me it is) Voltage and current are proportional and i always thought of current as depending on how large voltage is. i asked my teachers but they couldn't/wouldn't tell me :S
and then... my teacher contradicted what she said earlier about more voltage = less current.
cos there was a question, 2008 HSC paper, q10 - would you use a step-up or step-down transformer for a transistor.
and my teacher said "step down" because u want low voltage and thus low current by ohm's law
need help big time
i asked a phys sub, he said it was all about impedance matching but i didnt really get what he was going on about - didnt really answer my question.
p.s. yes you can apply Ohm's Law to AC even though it gets more complicated. think impedance is the key to the answer? *confused*
and then... my teacher contradicted what she said earlier about more voltage = less current.
cos there was a question, 2008 HSC paper, q10 - would you use a step-up or step-down transformer for a transistor.
and my teacher said "step down" because u want low voltage and thus low current by ohm's law
need help big time
i asked a phys sub, he said it was all about impedance matching but i didnt really get what he was going on about - didnt really answer my question.
p.s. yes you can apply Ohm's Law to AC even though it gets more complicated. think impedance is the key to the answer? *confused*