Two straight parallel wires, both carrying $10$ $ampere$ in the same direction attract each other with a force of $1 \times {10^{ - 3}}\,N$. If both currents are doubled, the force of attraction will be
A$1 \times {10^{ - 3}}\,N$
B$2 \times {10^{ - 3}}\,N$
C$4 \times {10^{ - 3}}\,N$
D$0.25 \times {10^{ - 3}}\,N$
Easy
Download our app for free and get started
C$4 \times {10^{ - 3}}\,N$
c (c) $F = \frac{{{\mu _0}}}{{4\pi }}\frac{{2{i_1}{i_2}}}{a} = {10^{ - 3}}\,N$
When current in both the wires is doubled, then
$F' = \frac{{{\mu _0}}}{{4\pi }}\frac{{2\left( {2{i_1} \times 2{i_2}} \right)}}{a} = 4 \times {10^{ - 3}}\,N$
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.*
Due to the flow of current in a circular loop of radius $R$, the magnetic field produced at the centre of the loop is $B$. The magnetic moment of the loop is :-
A thin disc of radius $R$ and mass $M$ has charge $q$ uniformly distributed on it. It rotates with angular velocity $\omega$. The ratio of magnetic moment and angular momentum for the disc is
Current is flowing through a conducting hollow pipe whose area of cross-section is shown in the figure. The value of magnetic induction will be zero at
A conductor lies along the $z-$axis $a$ $-1.5$$ \le Z < 1.5\,m$ carries a fixed current of $10.0\ A$ in $ - {\hat a_z}$ direction (see figure). For a field $\vec B$ $=$ $3.0 \times 10^{-4}$ $e^{-0.2x}$ ${\hat a_y}\,T$ find the power required to move the conductor at constant speed to $x = 2.0\ m, y = 0\ m$ in $5 \times 10^{-3}\ s$. Assume parallel motion along the $x-$axis........$ W$
A moving coil galvanometer has $N$ number of turns in a coil of effective area $A$, it carries a current $I$. The magnetic field $B$ is radial. The torque acting on the coil is
A $50\,\Omega $ resistance is connected to a battery of $5\,V$. A galvanometer of resistance $100\, \Omega $ is to be used as an ammeter to measure current through the resistance, for this a resistance $r_s$ is connected to the galvanometer. Which of the following connections should be employed if the measured current is within $1\% $ of the current without the ammeter in the circuit ?
An electron is the ground state of hydrogen atom is revolving in anticlockwise direction in a circular orbit of radius $'r'$. The atom is placed is a unifom magnetic field $B$ in such a way magnetic moment of orbital electron makes an angle $30^o$ with the magnetic field. The torque experienced by orbital electon is
An ammeter reads upto $1\, ampere$. Its internal resistance is $0.81\, ohm$. To increase the range to $10\, A$ the value of the required shunt is ............ $\Omega $