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# Voltage Drop Across Combination Circuit watch

1. Ok guys, I had a quick question for all the fellow physics lovers. I had an assignment graded and I personally think that my tutor is full of s***. But I wanted to ask everyone here first. In the above circuit (sorry for the tiny picture), theres a thermistor wired parallel with a 1200 ohm resistor and this parallel system is wired in series with the resistor on the right, which has a resistance of 540 ohms. The ammeter reads 10 mA, or 0.01 amps, and the whole circuit is attached to a battery with a supply voltage of 15 volts. Assuming that the battery has a negligible internal resistance, what is the potential difference across each resistors?

According to my logic, the ratio of voltage supplied has to be equal to the ratio of the resistors. Therefore, when you do the math, it comes out that the 540 ohm resistor has a pd of 4.7 V and the resistor with 1200 ohms has a pd of 10.3 V. Is the math behind this flawed???
2. (Original post by PascalSauerborn)

Ok guys, I had a quick question for all the fellow physics lovers. I had an assignment graded and I personally think that my tutor is full of s***. But I wanted to ask everyone here first. In the above circuit (sorry for the tiny picture), theres a thermistor wired parallel with a 1200 ohm resistor and this parallel system is wired in series with the resistor on the right, which has a resistance of 540 ohms. The ammeter reads 10 mA, or 0.01 amps, and the whole circuit is attached to a battery with a supply voltage of 15 volts. Assuming that the battery has a negligible internal resistance, what is the potential difference across each resistors?

According to my logic, the ratio of voltage supplied has to be equal to the ratio of the resistors. Therefore, when you do the math, it comes out that the 540 ohm resistor has a pd of 4.7 V and the resistor with 1200 ohms has a pd of 10.3 V. Is the math behind this flawed???
Doesn't the thermistor have its own resistance? Do you know the actual answer by the way; I've got something but it's been a while since I did physics so if it's wrong don't want to waste time going through it lol
3. As 13 1 20 8 42 said, the thermistor has a resistance, and so the resistance of the combination of the thermistor and 1200ohm resister is not 1200 ohms.

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