In the circuit diagram shown,the two resistance wires $A$ and $B$ are of the same area of cross-section and same material,but $A$ is longer than $B$. Which ammeter,$A_{1}$ or $A_{2}$,will indicate a higher reading for current? Give a reason.

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(B) Ammeter $A_{2}$ will show a higher reading.
According to the formula for resistance,$R = \rho \frac{l}{A}$,where $\rho$ is the resistivity,$l$ is the length,and $A$ is the area of cross-section.
Since both wires have the same material ($\rho$ is constant) and the same area of cross-section,the resistance is directly proportional to the length $(R \propto l)$.
Given that wire $A$ is longer than wire $B$,the resistance of wire $A$ $(R_{A})$ is greater than the resistance of wire $B$ $(R_{B})$.
According to Ohm's law,$I = \frac{V}{R}$. Since both resistors are connected in parallel,the potential difference $(V)$ across them is the same.
Therefore,current is inversely proportional to resistance $(I \propto \frac{1}{R})$.
Since $R_{A} > R_{B}$,the current flowing through wire $A$ $(I_{A})$ will be less than the current flowing through wire $B$ $(I_{B})$.
Thus,ammeter $A_{2}$ (connected in series with wire $B$) will show a higher reading than ammeter $A_{1}$ (connected in series with wire $A$).

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