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ALL PHYSICS DOUBTS - POST HERE !!

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Ghost Of Highbury:

--- Quote from: Ari Ben Canaan on May 24, 2010, 04:00:32 pm ---R1 should be LESS than R2 for the Voltage output to BE HIGH.


Hence, the thermistor should have a lower resistance (example when heated) than the VARIABLE resistor in order for the V output to the transistor to EXCEED 0.6 V and hence trigger the transistor.

--- End quote ---

Yes, thats exactly wat i said. Whats the confusion about?

applying V-I*R, when R decreases (thermistor), the Voltage decreases. So, the other part, Vbe , the variable resistor part gets more voltage, and if V>0.6V is flowing throught the emitter of the transistor, the transistor switches on.

Mr.DitD:

--- Quote from: Ari Ben Canaan on May 24, 2010, 04:00:32 pm ---R1 should be LESS than R2 for the Voltage output to BE HIGH.


Hence, the thermistor should have a lower resistance (example when heated) than the VARIABLE resistor in order for the V output to the transistor to EXCEED 0.6 V and hence trigger the transistor.

--- End quote ---

I think u're right. But what is exactly "voltage output"!?!?

I have a very big issue with voltage!!!  ???

By the way can someone please explain the general functioning of the transistors!?!?!

Ghost Of Highbury:

--- Quote from: Mr.DitD on May 24, 2010, 04:06:07 pm ---I think u're right. But what is exactly "voltage output"!?!?

I have a very big issue with voltage!!!  ???

By the way can someone please explain the general functioning of the transistors!?!?!

--- End quote ---

The voltage in the emitter part of the transistor?

holtadit:

--- Quote from: Mr.DitD on May 24, 2010, 04:06:07 pm ---I think u're right. But what is exactly "voltage output"!?!?

I have a very big issue with voltage!!!  ???

By the way can someone please explain the general functioning of the transistors!?!?!

--- End quote ---

Dude, such questions are for three marks.

The MS gives three points - just memorise them; few days left to the exam and you have no other choice.

Malak:
http://www.freeexampapers.us/IGCSE/Physics/CIE/2006%20Nov/0625_w06_qp_1.pdf

Q15 Why is it D?

Q18 ans and Explaination

Q31 ans and Explaination

Thx :)

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