Five identical cells each of internal resistance $1\, \Omega$ and $emf \;5\, {V}$ are connected in series and in parallel with an external resistance $'R'.$ For what value of $'R',$ current in series and parallel combination will remain the same ? (in $\Omega$)
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.*
In a building there are $15$ bulbs of $45\; \mathrm{W}, 15$ bulbs of $100\; \mathrm{W}, 15$ small fans of $10 \;\mathrm{W}$ and $2$ heaters of $1 \;\mathrm{kW}$. The voltage of electric main is $220\; \mathrm{V}$. The minimum fuse capacity (rated value) of the building will be: .......... $A$
The heating coils rating at $220\, volt$ and producing $50\, cal/sec$ heat are available with the resistances $55\,\Omega $ , $110\,\Omega$ , $220\,\Omega $ and $440\,\Omega $. The heater of maximum power will be of............. $\Omega$
In the circuit shown in figure reading of voltmeter is $V_1$ when only $S_1$ is closed, reading of voltmeter is $V_2$ when only $S_2$ is closed. The reading of voltmeter is $V_3$ when both $S_1$ and $S_2$ are closed then
Two batteries of different $e.m.f.'s$ and internal resistance connected in series with each other and with an external load resistor. The current is $3.0 \,A$. When the polarity of one battery is reversed, the current becomes $1.0 \,A$. The ratio of the $e.m.f.'s$ of the two batteries is ............
Two resistors are connected $(a)$ in series $(b)$ in parallel. The equivalent resistance in the two cases are $9$ $ohm$ and $2$ $ohm$ respectively. Then the resistances of the component resistors are
To measure the temperature coefficient of resistivity $\alpha$ of a semiconductor, an electrical arrangement shown in the figure is prepared. The arm BC is made up of the semiconductor. The experiment is being conducted at $25^{\circ} \mathrm{C}$ and resistance of the semiconductor arm is $3 \mathrm{~m} \Omega$. Arm BC is cooled at a constant rate of $2^{\circ} \mathrm{C} / \mathrm{s}$. If the galvanometer $\mathrm{G}$ shows no deflection after $10 \mathrm{~s}$, then $\alpha$ is :
Four wires of equal length and of resistances $10$ $ ohms$ each are connected in the form of a square. The equivalent resistance between two opposite corners of the square is ............. $ohm$