Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*
Two batteries one of the $\mathrm{emf}$ $3\,V$, internal resistance $1$ ohm and the other of $\mathrm{emf}$ $15\, V$, internal resistance $2$ $\mathrm{ohm}$ are connected in series with a resistance $R$ as shown. If the potential difference between $a$ and $b$ is zero the resistance of $R$ in $\mathrm{ohm}$ is
Two resistances ${R_1}$ and ${R_2}$ are joined as shown in the figure to two batteries of $e.m.f.$ ${E_1}$ and ${E_2}$. If ${E_2}$ is short-circuited, the current through ${R_1}$ is
A potentiometer having the potential gradient of $2\, mV/cm$ is used to measure the difference of potential across a resistance of $10 \,\Omega$. If a length of $50\, cm$ of the potentiometer wire is required to get the null point, the current passing through the $10 \,\Omega$ resistor is (in $mA$)
When a wire of uniform cross-section $a$, length $l$ and resistance $R$ is bent into a complete circle, resistance between any two of diametrically opposite points will be
Dimensions of a block are $1\,cm \times 1\,cm \times 100\,cm$. If specific resistance of its material is $3 \times {10^{ - 7}}\,ohm - m$, then the resistance between the opposite rectangular faces is
A $10\,V$ battery with internal resistance $1\,\Omega $ and a $15\,V$ battery with internal resistance $0.6\,\Omega $ are connected in parallel to a voltmeter (see figure). The reading in the voltmeter will be close to ................ $V$