$A$ 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 :
  • A$4$
  • B$6$
  • C$8$
  • D$9$
Medium
art

Download our app
and 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

  • 1
    The internal resistance of a primary cell is $4\, ohm$. It generates a current of $0.2\, amp$ in an external resistance of $21\, ohm$. The rate at which chemical energy is consumed in providing the current is .............. $J/s$
    View Solution
  • 2
    A capacitor of $50 \,\mu {F}$ is connected in a circuit as shown in figure. The charge on the upper plate of the capacitor is $......\,\mu {C} .$
    View Solution
  • 3
    $12$ cells each having same $emf$ are connected in series with some cells wrongly connected. The arrangement is connected in series with an ammeter and two cells which are in series. Current is $3 \,A$ when cells and battery aid each other and is $2\, A$ when cells and battery oppose each other. The number of cells wrongly connected is
    View Solution
  • 4
    Two batteries of different emfs and different internal resistances are connected as shown. The voltage across $A B$ in volts is
    View Solution
  • 5
    A piece of wire of resistance $4\, ohms$ is bent through $180^o$ at its mid point and the two halves are twisted together, then the resistance is ............ $ohms$
    View Solution
  • 6
    $A$. The drift velocity of electrons decreases with the increase in the temperature of conductor.

    $B$. The drift velocity is inversely proportional to the area of cross-section of given conductor.

    $C$. The drift velocity does not depend on the applied potential difference to the conductor.

    $D$. The drift velocity of electron is inversely proportional to the length of the conductor.

    $E$. The drift velocity increases with the increase in the temperature of conductor.

    Choose the correct answer from the options given below:

    View Solution
  • 7
    Five resistances are connected as shown in the figure. The effective resistance between the points $A$ and $B$ is
    View Solution
  • 8
    Time taken by a $836\; W$ heater to heat $1\; litre$ of water from $10^{\circ} C$ to $40^{\circ} C$ is
    View Solution
  • 9
    When a current of $2\,A$ flows in a battery from negative to positive terminal, the potential difference across it is $12\,V$. If a current of $3\,A$ flows in the opposite direction potential difference across the terminals of the battery is $15\,V$, the emf of the battery is ............... $\mathrm{V}$
    View Solution
  • 10
    The number of dry cells, each of $e.m.f.$ $1.5\,volt$ and internal resistance $0.5\, ohm$ that must be joined in series with a resistance of $20\, ohm$ so as to send a current of $0.6\,A$ through the circuit is
    View Solution