Motional EMF in an Open Conductor

Q. A metal rod moves at a constant velocity in a direction perpendicular to its length. A constant uniform magnetic field exists in space in a direction perpendicular to the rod as well as its velocity. Select the correct statement(s) from the following

1. The entire rod is at the same electric potential
2. There is an electric field in the rod
3. The electric potential is highest at the centre of the rod and decreases towards its ends
4. The electric potential is lowest at the centre of the rod and increases towards its ends

Q.

A thin semicircular conducting ring of radius R is falling with its plane vertical, in a horizontal magnetic induction B. At the position MNQ, the speed of the ring is V and the potential difference developed across the ring is

1. 
   

2. Zero

3. 2RBV and Q is at higher potential

4. 
   

Q.

An aeroplane in which the distance between the tips of wings is 50 m is flying horizontally with a speed of 360 km/hr over a place where the vertical component of earth's magnetic field is $2.0$ x ${10}^{-4}weber/m^2$ . The potential difference between the tips of the wings would be

1. 0.1 V

2. 1.0 V

3. 0.2 V

4. 0.01 V

Q. The induced EMF in the rod is:

1. $Blv$
2. $Blvcos\theta$
3. $Blvsin\theta$
4. $zero$

Q. A conductor of resistance $3\Omega$ is moving with speed v = 6 m/s. B is uniform & is equal to 4 Tesla. Length of the conductor is 50 cm. If $R=5\Omega$, find the power dissipated in $5\Omega$.

1. 6 Watt
2. 15 Watt
3. 9 Watt
4. 11 Watt

Q. A conducting rod is moving in uniform field of $4\times {10}^2$ Tesla; speed of the rod is 6 m/s. Find the emf induced in the rod.

1. 72 volt
2. 96 volt
3. 312 volt
4. 288 volt

Q. A uniform magnetic field exists in the region given by $\overrightarrow{B}=3\hat{i}-5\hat{k}$. A rod of length $5m$ placed along $y-$axis is moved along $x-$axis with constant speed $1m{s}^{-1}$. Then induced emf in the rod is

1. Zero
2. $5V$
3. $10V$
4. $25V$

Q.

Figure shows a wire sliding on two parallel, condu cting rails placed at a separation l. A magnetic field B exicts in a direction perpendicular to the plane of the rails. What force is necessary to keep the wire moving at a constant velocity v ?

Q.

A wire of length 10 cm translates in a direction making an angle of 60^{circ} with its length. The plane of motion is perpendicular to a uniform magnetic field of 1.0 T that exists in the space. Find the emf induced between the ends of the rod if the speed of translation is $20cm{s}^{-1}$.

Q.

Figure shows a suare loop of side 5 cm being moved towards right at a constant speed of 1 cm.s. The front edge enters the 20 cm wide magnetic field at t= 0. Find the emf induced in the top at

(a) t = 2 s,

(b) t = 10 s,

(c) t = 22 s. and

(d) t = 30 s.