If a wire of resistance $R$ is melted and recasted to half of its length, then the new resistance of the wire will be
  • A$R/4$
  • B$R/2$
  • C$R$
  • D$2R$
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
    In the circuit shown, the point ‘$B$’ is earthed. The potential at the point ‘$A$’ is ............. $V$
    View Solution
  • 2
    In 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
  • 3
    Pick out the wrong statement
    View Solution
  • 4
    A battery of $e.m.f.$ $3\, volt$ and internal resistance $1.0\, ohm$ is connected in series with copper voltameter. The current flowing in the circuit is $1.5\, amperes$. The resistance of voltameter will be ........... $ohm$
    View Solution
  • 5
    A source of $e.m.f.$  $E = 15\,V$ and having negligible internal resistance is connected to a variable resistance so that the current in the circuit increases with time as $i = 1.2 t + 3$. Then, the total charge that will flow in first five second will be ............... $C$
    View Solution
  • 6
    There are two wires of the same length and of the same material and radii $r$ and $2r$ . The ratio of their specific resistance is
    View Solution
  • 7
    In the given circuit, with steady current, the potential drop across the capacitor must be
    View Solution
  • 8
    A potentiometer wire of length $L$ and a resistance $r$ are connected in series with a battery of e.m.f. $E_0$ and a resistance $r_1$. An unknown e.m.f. $E$ is balanced at a length $l$ of the potentiometer wire. The e.m.f. $E$ will be given by
    View Solution
  • 9
    A platinum resistance thermometer has a resistance of $50\,\Omega $ at $20\,^o C$. When dipped in a liquid the resistance becomes $76.8\,\Omega $. The temperature coefficient of resistance for platinum is $\alpha = 3.92 \times {10^{ - 3}}\,^o C$. The temperature of the liquid is .............. $^o C$
    View Solution
  • 10
    A series combination of two resistors $1\,\Omega $ each is connected to a $12\,V$ battery of internal resistance $0.4\,\Omega $. The current flowing through it will be ............... $A$
    View Solution