Hey there I am having trouble answering questions 17 in my practice book. I would like some help please.

material [2] Show that the unit in which resistivity is 17 A battery of e.m.f. 3.0V and negligible internal measured is Om [2] resistance is connected in series with a resistor of The resistance of a piece of wire of length 12 cm 1.5 kQ and a thermistor T as shown in the diagram and cross sectional area of 2.0 x 10 8 mm is below. At room temperature, the resistance of the 3.66 2. Determine the resistivity of this wire. [3] thermistor is 2.0 kQ. a Calculate the potential difference across the 13 a Derive an expression for two resistors in series. [ 4] thermistor at room temperature. [2] b Derive an expression for two resistors in parallel. [4] c Calculate the effective resistance between the points X and Y. [3 ] 1.5 kQ 102 3.0V B Xo 109 104 b A uniform resistance wire PQ of length 1.00m Yo is connected in parallel with the resistor and the 102 thermistor as shown below. A sensitive voltmeter is connected between the point B and a movable 14 For the circuit below calculate: contact M on the wire. a [4] b [3] P 1.5 kQ B 1.00m - M 50 A O 25 i Explain why, for a constant current in the he below s an wire, the potential difference between any al res two points on the wire is proportional to the F ON and distance between the two points. [2] The contact M is moved along PQ until the voltmeter reading is zero. 1 State the potential difference between the 9V contact at M and the point Q [1] 2 Calculate the length of the wire MQ. [2] iii The thermistor is cooled slightly. State and explain the effect on the length of the wire between M and Q for the voltmeter to remain at zero deflection. [2]