Rotating Conductors & AC Generator

A conductor of length $1$ m rotates vertically about one of its ends at angular velocity $5$ rad/s. If the horizontal component of earth's magnetic field is $0.2 \times 10^{-4}$ T, then the e.m.f. developed between the ends of the conductor is

A conducting rod AC of length $4L$ is rotated counter-clockwise about a point O in a uniform magnetic field $B$ directed into the paper. If $AO = L$ and $OC = 3L$ then ($\omega$ = angular speed)

A conducting rod AB of length $l$ is rotated about point O which lies between point A and B in a uniform magnetic field $\vec{B}$ directed into the paper. If length $AO = \frac{l}{3}$, then $(V_A - V_B)$ is $\{\omega =$ angular velocity$\}$

A conducting circular loop is rotated about its diameter at a constant angular speed of $100\text{ rad/s}$ in a magnetic field of 0.5 T perpendicular to the axis of rotation. When the loop is rotated by $30^\circ$ from the horizontal position, the induced EMF is 15.4 mV. The radius of the loop is ______ mm. $($ Take $\pi = \frac{22}{7})$

A metal rod of length $L$ rotates about one end at origin with a uniform angular velocity $\omega$. The magnetic field radially falls off as $B(r) = B_o e^{-\lambda r};\ \lambda$ being a positive constant. The emf induced (neglecting the centripetal force on electrons in the rod) is:

A uniform magnetic field of 0.4 T acts perpendicular to a circular copper disc 20 cm in radius. The disc is having a uniform angular velocity of 10 $\pi$ rad s-1 about an axis through its centre and perpendicular to the disc. What is the potential difference developed between the axis of the disc and the rim? $(\pi = 3.14)$

What is the phase difference between the flux linked with a coil rotating in a uniform magnetic field and the induced e.m.f. produced in it?

A coil of area A and N turns is rotating with angular velocity $\omega$ in a uniform magnetic field $\vec{B}$ about an axis perpendicular to $\vec{B}$. Magnetic flux $\varphi$ and induced emf $\varepsilon$ across it, at an instant when $\vec{B}$ is parallel to the plane of coil, are:

A metal rod of length ' $l$ ' rotates about one of its ends in a plane perpendicular to a magnetic field of induction ' $B$ '. If the e.m.f. induced between the ends of the rod is ' $e$ ', then the number of revolutions made by the rod per second is

A rod of length ' $l$ ' is rotated with angular velocity ' $\omega$ ' about its one end, perpendicular to a magnetic field of induction ' $B$ '. The e.m.f. induced in the rod is

A metal disc of radius R rotates with an angular velocity $\omega$ about an axis perpendicular to its plane passing through its centre in a magnetic field of induction B acting perpendicular to the plane of the disc. The induced e.m.f. between the rim and axis of the disc is

In an a. c. generator, when the plane of the coil is perpendicular to the magnetic field

A rod of length $60\text{ cm}$ rotates with a uniform angular velocity $20\text{ rad s}^{-1}$ about its perpendicular bisector, in a uniform magnetic field $0.5\text{ T}$. The direction of magnetic field is parallel to the axis of rotation. The potential difference between the two ends of the rod is _________ V.

A bicycle wheel of radius ' $R$ ' has ' $n$ ' spokes. It is rotating at the rate of ' $F$ ' r.p.m. perpendicular to the horizontal component of earth's magnetic field $\vec{B}$. The e.m.f. induced between the rim and the centre of the wheel is

A circular coil of resistance ' $R$ ', area ' $A$ ', number of turns ' N ' is rotated about its vertical diameter with angular speed ' $\omega$ ' in a uniform magnetic field of magnitude ' $B$ '. The average power dissipated in a complete cycle is

A circular coil of resistance $R$, area $A$, number of turns ' $N$ ' is rotated about its vertical diameter with angular speed ' $\omega$ ' in a uniform magnetic field of magnitude ' $B$ '. The average power dissipated in a complete cycle is

A coil of 200 turns and area $0.20\text{ m}^2$ is rotated at half a revolution per second and is placed in uniform magnetic field of $0.01\text{ T}$ perpendicular to axis of rotation of the coil. The maximum voltage generated in the coil is $\frac{2\pi}{\beta}$ volt. The value of $\beta$ is _______.

A ceiling fan having 3 blades of length $80\text{ cm}$ each is rotating with an angular velocity of 1200 $\text{rpm}$. The magnetic field of earth in that region is $0.5\text{ G}$ and angle of dip is $30^\circ$. The emf induced across the blades is $N\pi \times 10^{-5}\text{ V}$. The value of $N$ is _________.

A metallic rod of length 'L' is rotated with an angular speed of '$\omega$' normal to a uniform magnetic field 'B' about an axis passing through one end of rod as shown in figure. The induced emf will be:

A $20\text{ cm}$ long metallic rod is rotated with $210\text{ rpm}$ about an axis normal to the rod passing through its one end. The other end of the rod is in contact with a circular metallic ring. A constant and uniform magnetic field $0.2\text{ T}$ parallel to the axis exists everywhere. The emf developed between the centre and the ring is ____________ $\text{mV}$.

Take $\pi = \frac{22}{7}$

A metal disc of radius $R$ rotates with an angular velocity $\omega$ about an axis perpendicular to its plane passing through its centre in a magnetic field of induction $B$ acting perpendicular to the plane of the disc. The magnitude of induced emf between the rim and axis of the disc is

An emf is generated by an ac generator having 100 turn coil, of loop area $1\text{ m}^2$. The coil rotates at a speed of one revolution per second and placed in a uniform magnetic field of $0.05\text{ T}$ perpendicular to the axis of rotation of the coil. The maximum value of emf is :-

A metallic conductor of length 1 m rotates in a vertical plane parallel to east-west direction about one of its end with angular velocity 5 rad s${}^{-1}$. If the horizontal component of earth's magnetic field is 0.2 $\times$ 10$-$4 T, then emf induced between the two ends of the conductor is:

A circular coil of 1000 turns each with area 1m2 is rotated about its vertical diameter at the rate of one revolution per second in a uniform horizontal magnetic field of 0.07T. The maximum voltage generation will be ___________ V.

A circular coil of radius 8.0 cm and 20 turns is rotated about its vertical diameter with an angular speed of 50 rad s${}^{-1}$ in a uniform horizontal magnetic field of 3.0 $\times$ 10$-$2 T. The maximum emf induced the coil will be ................. $\times$ 10$-$2 volt (rounded off to the nearest integer)

A wheel with 20 metallic spokes each $1\text{ m}$ long is rotated with a speed of $120\text{ rpm}$ in a plane perpendicular to a magnetic field of $0.4\text{ G}$. The induced emf between the axle and rim of the wheel will be $(1\text{ G} = 10^{-4}\text{ T})$

An elliptical loop having resistance R, of semi major axis a, and semi minor axis b is placed in magnetic field as shown in the figure. If the loop is rotated about the x-axis with angular frequency $\omega$, the average power loss in the loop due to Joule heating is:

A planar loop of wire rotates in a uniform magnetic field. Initially at t = 0, the plane of the loop is perpendicular to the magnetic field. If it rotates with a period of 10 s about an axis in its plane then the magnitude of induced emf will be maximum and minimum, respectively at:

A circular coil of radius 10 cm is placed in a uniform magnetic field of 3.0 $\times$ 10–5 T with its plane perpendicular to the field initially. It is rotated at constant angular speed about an axis along the diameter of coil and perpendicular to magnetic field so that it undergoes half of rotation in 0.2 s. The maximum value of EMF induced (in $\mu$V) in the coil will be close to the integer _______.

A cycle wheel of radius 0.5 m is rotated with constant angular velocity of 10 rad/s in a region of magnetic field of 0.1 T which is perpendicular to the plane of the wheel. The EMF generated between its centre and the rim is,

A coil of cross-sectional area A having n turns is placed in a uniform magnetic field B. When it is rotated with an angular velocity $\omega,$ the maxium e.m.f. induced in the coil will be:

A wire loop is rotated in a magnetic field. The frequency of change of direction of the induced e.m.f. is

A metallic rod of length $'\ell'$ is tied to a string of length $2\ell$ and made to rotate with angular speed $\omega$ on a horizontal table with one end of the string fixed. If there is a vertical magnetic field $'B'$ in the region, the $e.m.f$ induced across the ends of the rod is

A metal conductor of length $1\text{ m}$ rotates vertically about one of its ends at angular velocity $5$ radians per second. If the horizontal component of earth's magnetic field is $0.2 \times 10^{-4}\text{ T},$ then the $e.m.f.$ developed between the two ends of the conductor is

In a uniform magnetic field of induction $B$ a wire in the form of a semicircle of radius $r$ rotates about the diameter of the circle with an angular frequency $\omega.$ The axis of rotation is perpendicular to the field. If the total resistance of the circuit is $R,$ the mean power generated per period of rotation is