Advertisements
Advertisements
Question
A conducting rod is moved with a constant velocity v in a magnetic field. A potential difference appears across the two ends _____________ .
Options
if `vec v " || "vec l`
if `vec v " || "vec B`
if `vec l " || "vec B`
None of these
Advertisements
Solution
None of these
The potential difference across the two ends is given by
`e=Bvl`
It is non-zero only
(i) if the rod is moving in the direction perpendicular to the magnetic field `(vec v bot vec B)`
(ii) if the velocity of the rod is in the direction perpendicular to the length of the rod `(vec v bot vec l)`
(iii) if the magnetic field is perpendicular to the length of the rod `vec l bot vec B`
Thus, none of the above conditions is satisfied in the alternatives given.
APPEARS IN
RELATED QUESTIONS
A metal rod `1/sqrtpi `m long rotates about one of its ends perpendicular to a plane whose magnetic induction is 4 x 10-3 T. Calculate the number of revolutions made by the rod per second if the e.m.f. induced between the ends of the rod is 16 mV.
Explain why, an electromagnet is called a temporary magnet.
The direction of current in the coil at one end of an electromagnet is clockwise. This end of the electromagnet will be:
(a) north pole
(b) east pole
(c) south pole
(d) west pole
State whether the following statement are true or false:
A motor works on the principle electric generator?
In which of the following case does the electromagnetic induction occur?
A magnet is moved through a loop of wire .
Welders wear special glass goggles while working. Why? Explain.
Welders wear special goggles or face masks with glass windows to protect their eyes from electromagnetic radiations. Name the radiations and write the range of their frequency.
Calculate the dimensions of (a) \[\int \overrightarrow{E} . d \overrightarrow{l,}\] (b) vBl and (c) \[\frac{d \Phi_B}{dt}.\] The symbols have their usual meaning.
State Fleming’s Right Hand Rule.
State the purpose of soft iron core used in making an electromagnet.
Draw a labelled diagram to make an electromagnet from a soft iron bar. Mark the polarity at its ends in your diagram. What precaution would you observe while making it?
Choose the correct option:
A conductor rod of length (l) is moving with velocity (v) in a direction normal to a uniform magnetic field (B). What will be the magnitude of induced emf produced between the ends of the moving conductor?
An alternating emf of 0.2 V is applied across an L-C-R series circuit having R = 4Q, C = 80µF, and L = 200 mH. At resonance the voltage drop across the inductor is
Shown in the figure below is a metre bridge set up with null deflection in the galvanometer. The value of the unknown resistance R is ______
Metal rings P and Q are lying in the same plane, where current I is increasing steadily. The induced current in metal rings is shown correctly in figure.
A cylindrical bar magnet is kept along the axis of a circular coil. If the magnet is rotated about its axis, then ____________.
What should be the core of an electromagnet?
For making a strong electromagnet the material of the core should be ______.
In the current carrying conductor (AOCDEFG) as shown, the magnetic induction at point O is ______.
(R1 and R2 are radii of CD and EF respectively. l = current in the loop, μ0 = permeability of free space)
Which type of force is experienced by a moving charge in a magnetic field?
