- AAlign in the direction of magnetic field.
- BAlign in the direction opposite to magnetic field.
- CRemain unaffected.
- DAlign randomly.
Explanation:
On applying an external magnetic field, to a ferromagnetic substance domains Align in the direction of magnetic field. as shown in figure of ferromagnetic substance.

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In a single slit diffraction experiment first minimum for red light (660 nm) coincides with first maximum of some other wavelength l'. The value of l' is
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(a) 4400 Å |
(b) 6600 Å |
(c) 2000 Å |
(d) 3500 Å |
A radio isotope has a half life of 75 years. The fraction of the atoms of this material that would decay in 150 years will be
|
(a) 66.6% |
(b) 85.5% |
(c) 62.5% |
(d) 75% |
A rod of length 20 cm is rotating with angular speed of 100 rps in a magnetic field of strength 0.5 T about it’s one end. What is the potential difference between two ends of the rod
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(a) 2.28 V |
(b) 4.28 V |
(c) 6.28 V |
(d) 2.5 V |
A beam with wavelength falls on a stack of partially reflecting planes with separation d. The angle q that the beam should make with the planes so that the beams reflected from successive planes may interfere constructively is (where n = 1, 2, ……)
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(a) |
(b) |
(c) |
(d) |