$A$ wire of length $L$ and $3$ identical cells of negligible internal resistances are connected in series. Due to the current, the temperature of the wire is raised by $\Delta T$ in time $t. N$ number of similar cells is now connected in series with a wire of the same material and cross section but of length $2L$. The temperature of the wire is raised by the same amount $\Delta T$ in the same time $t$. The value of $N$ is :
Medium
Download our appand get started for free
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.*
Similar Questions
- 1Three resistances $4\,\Omega $ each of are connected in the form of an equilateral triangle. The effective resistance between two corners isView Solution
- 2Two identical heaters rated $220\, volt$, $1000\, watt$ are placed in series with each other across $220 \,volt$ lines. If resistance do not change with temperature, then the combined power is ............. $watt$View Solution
- 3A wire of length $5\,m$ and radius $1\,mm$ has a resistance of $1\, ohm$. What length of the wire of the same material at the same temperature and of radius $2\,mm$ will also have a resistance of $1\, ohm$ .............. $m$View Solution
- 4In the meter bridge shown, the resistance $X$ has a negative temperature coefficient of resistance. Neglecting the variation in other resistors, when current is passed for some time, in the cirucit, balance point should shift towards.View Solution
- 5As the switch $S$ is closed in the circuit shown in figure, current passed through it is .............View Solution
- 6Seven resistances are connected as shown in the figure. The equivalent resistance between $A$ and $B$ is ............... $\Omega$View Solution
- 7The resistances of the four arms $P, Q, R$ and $S$ in a Wheatstone's bridge are $10\,ohm$, $30\,ohm$, $30\,ohm$ and $90\,ohm$, respectively. The e.m.f. and internal resistance of the cell are $7\,volt$ and $5\,ohm$ respectively. If the galvanometer resistance is $50\,ohm$, the current drawn from the cell will be ............... $A$View Solution
- 8A battery of $3.0\, V$ is connected to a resistor dissipating $0.5\, W$ of power. If the terminal voltage of the battery is $2.5\, V$ the power dissipated within the internal resistance is$.......W$View Solution
- 9In the given figure, the $emf$ of the cell is $2.2\, {V}$ and if internal resistance is $0.6\, \Omega$. Calculate the power dissipated in the whole circuit: (in $W$)View Solution
- 10A wire of length $10 \mathrm{~cm}$ and radius $\sqrt{7} \times 10^{-4} \mathrm{~m}$ connected across the right gap of a meter bridge. When a resistance of $4.5 \ \Omega$ is connected on the left gap by using a resistance box, the balance length is found to be at $60 \mathrm{~cm}$ from the left end. If the resistivity of the wire is $\mathrm{R} \times 10^{-7} \Omega \mathrm{m}$, then value of $\mathrm{R}$ is :View Solution