MCQ
Ferromagnetic ore properties are due to:
- Afilled inner sub-shells.
- Bvacant inner sub-shells.
- Cpartially filled inner sub-shells.
- Dall the sub-shells equally filled.
✓
Answer
- partially filled inner sub-shells.
Explanation:
Partially filled inner sub-shells, due to the magnetic moment of unpaired electrons in partially filled inner sub-shells which got align in a particular direction in the presence of external magnetic field.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
Two identical thin rings, each of radius a meter, are coaxially placed at a distance R meter apart. If Q1 coulomb and Q2 coulomb are respectively the charges uniformly spread on the two rings, the work done in moving a charge q coulomb from the centre of one ring to that of the other is:
An AC source rated 100V (rms) supplies a current of 10A (rms) to a circuit. The average power delivered by the source:
- Must be 1000W.
- May be 1000W.
- May be greater than 1000W.
- May be less than 1000W.
A spectral line λ = 5000 Å in the light coming from a distant star is observed as a 5200 Å. What will be recession velocity of the star
|
(a) 1.15 |
(b) 1.15 |
(c) 1.15 |
(d) 1.15 km/sec |
Consider a photon of a continuous X-ray coming from a Coolidge tube. Its energy comes from:
- The kinetic energy of the striking electron.
- The kinetic energy of the free electrons of the target.
- The kinetic energy of the ions of the target.
- An atomic transition in the target.
Sixty-four drops are jointed together to form a bigger drop. If each small drop has a capacitance C, a potential V, and a charge q, then the capacitance of the bigger drop will be
|
(a) C |
(b) 4C |
(c) 16C |
(d) 64C |
A long wire A carries a current of 10 amp. Another long wire B, Which is parallel to A and separated by 0.1m from A, carries a current of 5 amp, in the opposite direction to that in A. what is the magnitude and nature of the force experienced per unit length of B (
|
(a) Repulsive force of |
(b) Attractive force of |
|
(c) Repulsive force of 2π × |
(d) Attractive force of 2π |
The minimum energy required to excite a hydrogen atom from its ground state is
|
(a) 13.6 eV |
(b) -13.6 eV |
(c) 3.4 eV |
(d) 10.2 eV |
Ten grams of 57Co kept in an open container beta-decays with a half-life of 270 days. The weight of the material inside the container after 540 days will be very nearly:
- 10g
- 5g
- 2.5g
- 1.25g
Choose the correct answer from the alternatives given.
Displacement current goes through the gap between the plates of a capacitor when the charge of the capacitor.
Displacement current goes through the gap between the plates of a capacitor when the charge of the capacitor.
has half life 5700 years. At the end of 11400 years, the actual amount left is
|
(a) 0.5 of original amount |
(b) 0.25 of original amount |
|
(c) 0.125 of original amount |
(d) 0.0625 of original amount |