Advertisements
Advertisements
प्रश्न
A conducting rod is moved with a constant velocity v in a magnetic field. A potential difference appears across the two ends _____________ .
विकल्प
if `vec v " || "vec l`
if `vec v " || "vec B`
if `vec l " || "vec B`
None of these
Advertisements
उत्तर
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
संबंधित प्रश्न
A solenoid of length 1.5 m and 4 cm in diameter possesses 10 turns per metre. A current of 5 A is flowing through it. The magnetic induction at a point inside the solenoid along the axis is ............................. .
(μ0 = 4π × 10-7 Wb/Am)
- π × 10-5 T
- 2π × 10-5 T
- 3π × 10-5 T
- 4π × 10-5 T
What is electromagnetic induction?
State three ways in which the strength of an electromagnet can be increased.
Name two devices in which electromagnets are used and two devices where permanent magnets are used.
What condition is necessary for the production of current by electromagnetic induction?
When a wire is moved up and down in a magnetic field, a current is induced in the wire. What is this phenomenon known as?
A light metal disc on the top of an electromagnet is thrown up as the current is switched on. Why? Give reason.
The following diagram shows a fixed coil of several turns connected to a center zero galvanometer G and a magnet NS which can move in the direction shown in the diagram.
- Describe the observation in the galvanometer if
- The magnet is moved rapidly,
- The magnet is kept still after it has moved into the coil
- The magnet is then rapidly pulled out the coil.
- How would the observation in (i) of part (a) change if a more powerful magnet is used?
Fill in the blanks by writing (i) Only soft iron, (ii) Only steel, (iii) Both soft-iron and steel for the material of core and/or magnet.
D.C. motor ______.
State the purpose of soft iron core used in making an electromagnet.
Write Fleming’s right hand thumb rule with the help of diagram.
What for an inductor is used? Give some examples.
The magnetic flux passing through a coil perpendicular to its plane is a function of time and is given by OB = (2t3 + 4t2 + 8t + 8) Wb. If the resistance of the coil is 5 Ω, determine the induced current through the coil at a time t = 3 second.
A coil of 200 turns carries a current of 0.4 A. If the magnetic flux of 4 mWb is linked with each turn of the coil, find the inductance of the coil.
Using Lenz’s law, predict the direction of induced current in conducting rings 1 and 2 when the current in the wire is steadily decreasing.
There is a uniform magnetic field directed perpendicular and into the plane of the paper. An irregular shaped conducting loop is slowly changing into a circular loop in the plane of the paper. Then ______.
Ansari Sir was demonstrating an experiment in his class with the setup as shown in the figure below.
A magnet is attached to a spring. The magnet can go in and out of the stationary coil. He lifted the Magnet and released it to make it oscillate through the coil.
Based on your understanding of the phenomenon, answer the following question.
What will be observed when the Magnet starts oscillating through the coil. Explain the reason behind this observation.
A coil of one turn is made of a wire of certain length and then from the same length, a coil of two turns is made. If the same current is passed in both the cases, then the ratio of the magnetic inductions at their centres will be:
A current I = 10 sin(100π t) A is passed in first coil, which induces a maximum e.m.f of 5π volt in second coil. The mutual inductance between the coils is ______.
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)
