Figure shows a rectangular conductor PQRS in which the conductor PQ is free to move. The conductor PQ is moved towards the left with a constant velocity V as shown in the figure. Assume that there is no loss of energy due to friction.
What will be the magnetic flux linked with the loop PQRS and the motional emf?
To solve the problem regarding the rectangular conductor PQRS with the conductor PQ moving with a constant velocity \( V \), we need to find the magnetic flux linked with the loop and the motional emf.
Concept Used: The magnetic flux (\(\Phi\)) through a surface is given by:
\(\Phi = B \times A\)
where \( B \) is the magnetic field and \( A \) is the area of the surface. For a rectangle, \( A = l \times x \) where \( l \) is the length and \( x \) is the distance moved.
The motional emf (\(\varepsilon\)) induced in a conductor moving in a magnetic field is given by:
\(\varepsilon = B \times l \times V\)
where \( V \) is the velocity of movement.
- Calculate the Magnetic Flux:
- The area \( A = l \times x \).
- Thus, the magnetic flux \(\Phi = B \times (l \times x) = Blx\).
- Calculate the Motional EMF:
- The motional emf as derived from the formula is \(\varepsilon = B \times l \times V\).
By using the above considerations, the correct answer is:
- Magnetic flux = \(Blx\)
- Motional emf = \(BIV\)
Thus, the option Magnetic flux = Blx; Motional emf = BIV is correct.
Important Questions from Electromagnetic Induction
In a pair of adjacent coils, for a change of current in one of the coils from 0 A to 10 A in 0.25 s, the magnetic flux in the adjacent coil changes by 15 Wb. The mutual inductance of the coils is:
A 50 Hz AC current of crest value 1 A flows through the primary of a transformer. If the mutual inductance between the primary and secondary is 0.5 H, the crest voltage induced in the secondary is:
A long solenoid of diameter 0.1 m has 2 × 104 turns per meter. At the center of the solenoid, a coil of 100 turns and radius 0.01 m is placed with its axis coinciding with the solenoid axis. The current in the solenoid reduces at a constant rate to 0 A from 4 A in 0.05 s. If the resistance of the coil is 10π² Ω, then the total charge flowing through the coil during this time is:
Lower half of a convex lens is made opaque. Which of the following statements describes the image of the object placed in front of the lens?
A transformer has an efficiency of 80%. It works at 3 kW and 120 V. If the secondary voltage is 240 V, what will be the secondary current?
