This is a circuit

State and explain how the reading on the ammeter changes when the temperature of the thermistor is increased.

When a potential difference of $1.5 \mathrm{V}$, is applied across a $5.0 \mathrm{m}$, length of insulated copper wire, a current of $0.24 \mathrm{A}$, is measured in it.Calculate the resistance of per unit length of wire.

When a potential difference of $1.5 \mathrm{V}$, is applied across a $5.0 \mathrm{m}$, length of insulated copper wire, a current of $0.24 \mathrm{A}$, is measured in it The resistivity of copper is $1.69\times {10}^{-8}\Omega \mathrm{m}$. Calculate the diameter of the wire.

This diagram shows a piece of silicon of width $32 \mathrm{mm}$ and length $36 \mathrm{mm}$. The resistance of the silicon between the points $\mathrm{P}$ and $\mathrm{Q}$ is $1.1\mathrm{M}\Omega$. Silicon has a resistivity of $2.3\times {10}^3\Omega \mathrm{m}$.

Calculate the thickness of the piece of silicon.

This diagram shows a piece of silicon of width $32 \mathrm{mm}$ and length $36 \mathrm{mm}$. The resistance of the silicon between the points $\mathrm{P}$ and $\mathrm{Q}$ is $1.1\mathrm{M}\Omega$. Silicon has a resistivity of $2.3\times {10}^3\Omega \mathrm{m}$.

Calculate the current that would pass through the silicon if a potential difference of $12\mathrm{V}$ were applied across $\mathrm{P} \& \mathrm{Q}$.

This diagram shows a piece of silicon of width $32 \mathrm{mm}$ and length $36 \mathrm{mm}$. The resistance of the silicon between the points $\mathrm{P}$ and $\mathrm{Q}$ is $1.1\mathrm{M}\Omega$. Silicon has a resistivity of $2.3\times {10}^3\Omega \mathrm{m}$.

Describe how the current would change if it were large enough to cause the silicon to become significantly warmer.