$A$ circuit is comprised of eight identical batteries and a resistor $R = 0.8\,\Omega$. Each battery has an $emf$ of $1.0\, V$ and internal resistance of $0.2\,\Omega$. The voltage difference across any of the batteries is ............. $V$.

The potential difference $V_B - V_A$ in the network shown is ............. $V$.

One end of a Nichrome wire of length $2L$ and cross-sectional area $A$ is attached to an end of another Nichrome wire of length $L$ and cross-sectional area $2A$. If the free end of the longer wire is at an electric potential of $8.0\,V$,and the free end of the shorter wire is at an electric potential of $1.0\,V$,the potential at the junction of the two wires is equal to ............. $V$.

In the circuit shown,if a conducting wire is connected between points $A$ and $B,$ the current in this wire will

Two resistances of $400 \Omega$ and $800 \Omega$ are connected in series with a $6 \text{ V}$ battery of negligible internal resistance. $A$ voltmeter of resistance $10000 \Omega$ is used to measure the potential difference across the $400 \Omega$ resistor. The error in the measurement of potential difference in volts is approximately:

The series combination of two batteries,both of the same emf $10 \; V,$ but different internal resistances of $20 \; \Omega$ and $5 \; \Omega,$ is connected to the parallel combination of two resistors $30 \; \Omega$ and $R \; \Omega.$ If the voltage difference across the battery of internal resistance $20 \; \Omega$ is zero,the value of $R$ (in $\Omega$) is: