The e.m.f. of a cell is $E\, volts$ and internal resistance is $r$ $ohm$. The resistance in external circuit is also $r$ $ohm$. The p.d. across the cell will be
  • A$E/2$
  • B$2E$
  • C$4E$
  • D$E/4$
Easy
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
    $A$ wire of cross-section area $A$, length $L_1$, resistivity $\rho_1$ and temperature coefficient of resistivity $\alpha_1$ is connected to a second wire of length $L_2$, resistivity $\rho_2$ , temperature coefficient of resistivity $\alpha_1$ and the same area $A$, so that wire carries same current. Total resistance $R$ is independent of temperature for small temperature change if (Thermal expansion effect is negligible)
    View Solution
  • 2
    A constant voltage is applied between the two ends of a metallic wire. If both the length and the radius of the wire are doubled, the rate of heat developed in the wire
    View Solution
  • 3
    Voltmeter reads potential difference across the terminals of an old battery as $1.2\,volt$ , while a potentiometer reads $1.4\,volt$ . The internal resistance of battery is $40\,\Omega $ , then voltmeter resistance is .............. $\Omega$
    View Solution
  • 4
    A battery of $emf$ $10\,V$ is connected to resistances as shown in the figure. The potential difference between $A$ and $B,\,\,(V_A -V_B)$ is ................ $V$
    View Solution
  • 5
    Two indentical electric lamps marked $500\, W, \,\,220\, V$ are connected in series and then joined to a $110\, V$ line. The power consumed by each lamp is
    View Solution
  • 6
    A $d.c.$ main supply of $e.m.f.\, 220\, V$ is connected across a storage battery of $e.m.f.\, 200\, V$ through a resistance of $1\,\Omega $. The battery terminals are connected to an external resistance $'R'$ . The minimum value of $'R'$, so that a current passes through the battery to charge it is ............... $\Omega$
    View Solution
  • 7
    When the key $K$ is pressed at time $t = 0$, which of the following statements about the current $I$ in the resistor $AB$ of the given circuit is true
    View Solution
  • 8
    An electric bulb is designed to draw power $P_0$ at voltage $V_0$. If the voltage is $V$ it draws a power $P$. Then
    View Solution
  • 9
    A student in a town in India, where the price per unit ( $1$ unit $=1 \,kWh$ ) of electricity is $₹ 5.00$, purchases a $1 \,kVA$ $UPS$ (uninterrupted power supply) battery. A day before the exam, $10$ friends arrive to the student's home with their laptops and all connect their laptops to the $UPS$. Assume that each laptop has a constant power requirement of $90 \,W$. Consider the following statements.

    $I.$ All the $10$ laptops can be powered by the $UPS$, if connected directly.

    $II.$ All the $10$ laptops can be powered, if connected using an extension box with a $3 \,A$ fuse.

    $III.$ If all the $10$ friends use the laptop for $5 \,h$, then the cost of the consumed electricity is about $₹ 22.50.$

    Select the correct option with the true statements.

    View Solution
  • 10
    In the figure, the value of resistors to be connected between $C$ and $D$ so that the resistance of the entire circuit between $A$ and $B$ does not change with the number of elementary sets used is
    View Solution