Umakant Kondapure, Collin Fernandes, Nipun Bhatia, Vikram Bathula and, Ketki Deshpande Solutions for Chapter: Magnetic Effect of Electric Current, Exercise 4: Evaluation Test

A wire of cross-sectional area $A$ forms $3$ sides of a square and is free to turn about axis $XX$". If the structure is deflected by $\theta$ from vertical when current $I$ is passed through it; in a magnetic field $B$ acting vertically upward and density of wire is $\rho$, the value of $B$ is given by

Two long coaxial conducting cylinders of radii $R_1$ and $R_2(R_2>R_1)$ are maintained at a potential difference of $V$ with the help of a d.c. source such that current$I$ flows in the arrangement. An electron enters the space (away from the reader) between the cylinders leaves undeflected. The velocity of electron is

A wider conductor strip of width $x$ is bent into a slender tubing of radius $r$ with its two ends forming two plane extensions. A current $I$ flowing through it gives magnetic field in tubular portion given by

A long wire carrying a steady current is bent into a single coil such that magnetic induction at centre is $B$. Then same wire is bent to form a coil of smaller radius of $4$ turns when magnetic induction at centre is $B\text{'}$. Then

Find the magnetic moment of a thin round loop with current if the radius of the loop is equal to $r$ and the magnetic induction at its centre is equal to $X$.

A micro ammeter has a resistance of $100 \mathrm{\Omega }$ and a full scale range of $50 \mathrm{\mu A}$. It can be used as a voltmeter or as a higher range ammeter, provided a resistance is added to it. Pick the correct range and resistance combination from the following.

A circular coil of radius $r$ carries a current $I$. The magnetic field at its centre is $B$. At what distance from the centre, on the axis of the coil the magnetic field will be $\frac{B}{27}$?

An infinite straight conductor carrying current $2i$ is split into a loop of radius $r$ as shown in the figure. The magnetic field at the centre of the coil is