Current Electri...

Copper and Carbon wires are connected in series and the combined resistor is kept at $$\displaystyle { 0 }^{ \circ  }C$$. Assuming the combined resistance does not vary with temperature, the ratio of the resistances of Carbon and Copper wires at $$\displaystyle { 0 }^{ \circ  }C$$ is:
 (Temperature coefficients of resistivity of Copper and Carbon respectively are $$\displaystyle 4\times { { 10 }^{ -3 } }/{ ^{ \circ  }{ C } }$$ and $$\displaystyle -0.5\times { { 10 }^{ -3 } }/{ ^{ \circ  }{ C } }$$)

The electric current $$i$$ in the circuit shown is:

A group of $$N$$ cells whose emf varies directly with the internal resistance as per the equation $$\displaystyle { E }_{ N }=1.5{ r }_{ N }$$ are connected as shown in the figure above. The current $$I$$ in the circuit is:

A potentiometer wire is $$100\ $$cm long and a constant potential difference is maintained across it. Two cells are connected in series first to support one another and then in opposite direction. The balance points are obtained at $$50$$ cm and $$10$$ cm from the positive end of the wire in the two cases. The ratio of emf's is:

The resistance across $$A$$ and $$B$$ in the given figure will be:

In shown diagram, if voltage of battery is doubled and resistance kept constant then what is the new Power dissipated at resistor(Consider $$P$$ was the initial power dissipation) ?

A potentiometer has uniform potential gradient. The specific resistance of the material of the potentiometer wire is $$\displaystyle { 10 }^{ -7 }$$ ohm-metre and the current passing through it is $$0.1$$ ampere, cross-section of the wire is $$\displaystyle { 10 }^{ -6 }{ m }^{ 2 }$$. The potential gradient along the potentiometer wire is:

If a third identical resistor is added in parallel in a circuit of two identical parallel resistors. Calculate the ratio of the new equivalent resistance to the old?

Three resistor of $$10 \Omega$$, $$20 \Omega$$, and $$30 \Omega$$ are connected in parallel in a circuit. Calculate the equivalent resistance.

This question relates to the DC circuit shown below.
The values for current, voltage, and resistance in the circuit are graphed from point A through point G in the graphs directly below.
Which of the graphs shows the voltage from point A to point G?