Embibe Experts Solutions for Chapter: Current Electricity, Exercise 3: Exercise - 3

Consider two different metallic strips $(1 \mathrm{and} 2)$ fo the same material. Their lengths are the same, width  are ${\mathrm{w}}_1$ and  ${\mathrm{w}}_{2 }$ and thicknesses are ${\mathrm{d}}_1$ and ${\mathrm{d}}_2$, respectively. Two points $\mathrm{K}$ and $\mathrm{M}$ are symmetrically located on the opposite faces parallel to the $\mathrm{x}-\mathrm{y}$ plane (see figure). ${\mathrm{V}}_1$ and ${\mathrm{V}}_2$ are the potential differences between $\mathrm{K}$ and $\mathrm{M}$ in strips $1$ and $2$, respectively. Then, for a given current $\mathrm{I}$ flowing through them in a given magnetic field strength $\mathrm{B}$, the correct statement(s) is (are)

A superconductor has$T_{\mathrm{C}} \left(0\right)=100 \mathrm{K}.$When a magnetic field of$7.5$Tesla is applied, its $T_{\mathrm{C}}$ decreases to $75 \mathrm{K}.$For this material, one can definitely say that when:

By increasing the temperature, the specific resistance of a conductor and semiconductor

A strip of copper and another of germanium are cooled from room temperature to $80 \mathrm{K}.$ The resistance of 

A $5 \mathrm{V}$ battery with internal resistance $2 \mathrm{\Omega }$ and a $2 \mathrm{V}$ battery with internal resistance $1 \mathrm{\Omega }$ are connected to a $10 \mathrm{\Omega }$ resistor as shown in the figure.

 The current in the $10 \mathrm{\Omega }$ resistor is 

Two batteries with e.m.f $12\mathrm{V}$ and $13\mathrm{V}$ are connected in parallel across a load resistor of $10\mathrm{\Omega }$. The internal resistance of the two batteries are $1\mathrm{\Omega }$ and $2\mathrm{\Omega }$ respectively. The voltage across the load lies between

In a potentiometer experiment, it is found that no current passes through the galvanometer when the terminals of the cell are connected across $52\mathrm{cm}$ of the potentiometer wire. If the cell is shunted by resistance of $5 \mathrm{\Omega }$, a balance is found when the cell is connected across $40 \mathrm{cm}$ of the wire. Find the internal resistance of the cell.

On interchanging the resistances, the balance point of a meter bridge shifts to the left by $10 \mathrm{cm}$. The resistance of their series combination is $1\mathrm{K\Omega }$. How much was the resistance on the left slot before interchanging the resistances ?