A uniform wire of resistance $R$ is uniformly compressed along its length, until its radius becomes $n$ times the original radius. Now resistance of the wire becomes
Easy
Download our app for free and get startedPlay store
(a) $\frac{{{R_1}}}{{{R_2}}} = {\left( {\frac{{{r_2}}}{{{r_1}}}} \right)^4} \Rightarrow \frac{R}{{{R_2}}} = {\left( {\frac{{nr}}{r}} \right)^4} \Rightarrow {R_2} = \frac{R}{{{n^4}}}$.
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 figure shows a network of resistors and $a$ battery. If $1\,A$ current flowsthrough the branch $CF$, then answer the following questions The current through
    View Solution
  • 2
    When the current $i$ is flowing through a conductor, the drift velocity is $v$. If $2i$ current is flowed through the same metal but having double the area of cross-section, then the drift velocity will be
    View Solution
  • 3
    Find the current in the loop.
    View Solution
  • 4
    The figure shows a circuit diagram of a ‘Wheatstone Bridge’ to measure the resistance $G$ of the galvanometer. The relation $\frac{P}{Q} = \frac{R}{G}$ will be satisfied only when
    View Solution
  • 5
    A capacitor of capacitance $5\,\mu F$ is connected to a source of constant $emf$ of $200\,V$ for a long time, then the switch was shifted to contact $2$ from contact $1$ . The total amount of heat generated in the $500\,\Omega $ resistance, thereafter is
    View Solution
  • 6
    Three $60\, W$ light bulbs are mistakenly wired in series and connected to a $120\,V$ power supply. Assume the light bulbs are rated for single connection to $120\,V$. With the mistaken connection, the power dissipated by each bulb is: .................. $W$
    View Solution
  • 7
    The current in the adjoining circuit will be
    View Solution
  • 8
    Two batteries of $e.m.f.$ $4\,V$ and $8 \,V$ with internal resistances $1\, \Omega$ and $2\,\Omega$ are connected in a circuit with a resistance of $9 \,\Omega$ as shown in figure. The current and potential difference between the points $P$ and $Q$ are
    View Solution
  • 9
    In the circuit shown the cells $A$ and $B$ have negligible resistance. For $V _{ A }=12\; V , R _{1}=500\; \Omega$ and $R =100\; \Omega$ the galvanometer $(G)$ shows no deflection. The value of $V_{B}$ is .... $V$
    View Solution
  • 10
    The capacitor $C$ is initially without charge.$X$ is now j oined to $Y$ for a long time, during which $H_1$ heat is produced in the resistance $R$. $X-Y$ connection is removed and $X$ is now joined to $Z$ for a long time, during which heat $H_2$ is produced in $R$.
    View Solution