Advertisements
Advertisements
प्रश्न
and ```vecE` and `vecB`denote electric and magnetic fields in a frame S and `vecE`→ and `vecB` in another frame S' moving with respect to S at a velocity `vecV` Two of the following equations are wrong. Identify them.
(a) `B_y^, = B_y + (vE_z)/c^2`
(b) `E_y^' = E_y - (vB_z)/(c^2)`
`(c) Ey = By + vE_z`
`(d) E_y = E_y + vB_z`
Advertisements
उत्तर
(b) `E_y^' = E_y - (vB_z)/(c^2)`
`(c) Ey = By + vE_z`
Electric force due to a charged particle is q E and magnetic force is q V B.
We can sort out the two wrong equations using dimensional analysis. Now, equating the above two forces. we get:
E = V B
Hence, analysing the answers using dimensional analysis, we see that the second term on the RHS of the equations (b) and (c) are not dimensionally correct. Thus, the options (b) and (c) are wrong.
APPEARS IN
संबंधित प्रश्न
What is the magnitude of magnetic force per unit length on a wire carrying a current of 8 A and making an angle of 30° with the direction of a uniform magnetic field of 0.15 T?
Two long and parallel straight wires A and B carrying currents of 8.0 A and 5.0 A in the same direction are separated by a distance of 4.0 cm. Estimate the force on a 10 cm section of wire A.
Two parallel, long wires carry currents i1 and i2 with i1 > i2. When the currents are in the same direction, the magnetic field at a point midway between the wires is 10 µT. If the direction of i2 is reversed, the field becomes 30 µT. The ratio i1/i2 is
A current of 10 A is established in a long wire along the positive z-axis. Find the magnetic field \[\vec{B}\] at the point (1 m, 0, 0).
A copper wire of diameter 1.6 mm carries a current of 20 A. Find the maximum magnitude of the magnetic field `vecB` due to this current.
A transmission wire carries a current of 100 A. What would be the magnetic field B at a point on the road if the wire is 8 m above the road?
The magnetic field existing in a region is given by `vecB = B_0(1 + x/1)veck` . A square loop of edge l and carrying a current i, is placed with its edges parallel to the x−y axes. Find the magnitude of the net magnetic force experienced by the loop.
Figure shows a metallic wire of resistance 0.20 Ω sliding on a horizontal, U-shaped metallic rail. The separation between the parallel arms is 20 cm. An electric current of 2.0 µA passes through the wire when it is slid at a rate of 20 cm s−1. If the horizontal component of the earth's magnetic field is 3.0 × 10−5 T, calculate the dip at the place.

Two parallel wires carry equal currents of 10 A along the same direction and are separated by a distance of 2.0 cm. Find the magnetic field at a point which is 2.0 cm away from each of these wires.
Three coplanar parallel wires, each carrying a current of 10 A along the same direction, are placed with a separation 5.0 cm between the consecutive ones. Find the magnitude of the magnetic force per unit length acting on the wires.
Do magnetic forces obey Newton’s third law. Verify for two current elements dl1 = dlî located at the origin and dl2 = dlĵ located at (0, R, 0). Both carry current I.
Beams of electrons and protons move parallel to each other in the same direction. They ______.
Two long straight parallel current-carrying conductors are kept ‘a’ distant apart in the air. The direction of current in both the conductors is the same. Find the magnitude of force per unit length and the direction of the force between them. Hence define one ampere.
The figure below are two long, parallel wires carrying current in the same direction such that I1 < I2.

- In which direction will wire I1 move?
- If the direction of the current I2 is reversed, in which direction will the wire I1 move now?
When two long, straight, current-carrying conductors are placed parallel to each other and the currents flow in the same direction, the conductors:
The force per unit length between two long parallel current-carrying conductors carrying currents I₁ and I₂, separated by a perpendicular distance d, is given by:
The magnetic force between two long parallel current-carrying conductors acts:
