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प्रश्न
Pyrolusite ore is _______.
विकल्प
MnO
MnO2
Mn2O7
Mn2O3
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उत्तर
Pyrolusite ore is MnO2.
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संबंधित प्रश्न
What is ferromagnetism?
Iron (z=26) is highly ferromagnetic. Explain.
Analysis shows that nickel oxide has the formula Ni0.98O1.00. What fractions of nickel exist as Ni2+ and Ni3+ ions?
Explain the following with suitable examples:
Ferrimagnetism
Explain the following with suitable examples:
Antiferromagnetism
Explain why:
(i) Transition elements form coloured compounds.
(ii) Interhalogen compounds are more reactive than their constituent elements.
(iii) Cu+ is diamagnetic but Cu2+ is paramagnetic. (Z = 29)
Give reason for the following :
Sulphur in vapour state shows paramagnetic behaviour.
The BH curve for a ferromagnetic material is shown in the figure. The material is placed inside a long solenoid which contains 1000 turns/cm. The current that should be passed in the solenonid to demagnetize the ferromagnet completely is
Compare dia, para and ferromagnetism.
What happens to the domains in a ferromagnetic material in the presence of external magnetic field?
Compare the properties of soft and hard ferromagnetic materials.
Example of ferromagnetic substance is ____________.
Which type of substances would make better permanent magnets?
Which of the following statements is not true?
Which of the following statements are correct?
(i) Ferrimagnetic substances lose ferrimagnetism on heating and become paramagnetic.
(ii) Ferrimagnetic substances do not lose ferrimagnetism on heating and remain ferrimagnetic.
(iii) Antiferromagnetic substances have domain structures similar to ferromagnetic substances and their magnetic moments are not cancelled by each other.
(iv) In ferromagnetic substances all the domains get oriented in the direction of magnetic field and remain as such even after removing magnetic field.
Which one of the following would feel attraction when placed in magnetic field: Co2+, Ag+, Ti4+, Zn2+
Some of the polar crystals when heated produces small electrical current. This phenomenon is called ______.
The correct order of bond strength is ______.
Which of the following statements are correct?
- Electric monopoles do not exist whereas magnetic monopoles exist.
- Magnetic field lines due to a solenoid at its ends and outside cannot be completely straight and confined.
- Magnetic field lines are completely confined within a toroid.
- Magnetic field lines inside a bar magnet are not parallel.
- χ = -1 is the condition for a perfect diamagnetic material, where x is its magnetic susceptibility.
Which of the following is not paramagnetic?
Match items of List - I with those of List - II:
| List - I | List - II | ||
| (Property) | (Example) | ||
| (A) | Diamagnetism | (i) | MnO |
| (B) | Ferrimagnetism | (ii) | O2 |
| (C) | Paramagnetism | (iii) | NaCl |
| (D) | Antiferromagnetism | (iv) | Fe3O4 |
Choose the most appropriate answer from the options given below:
Give a reason for the following:
Cu+2 salts are paramagnetic, while Cu+ salts are diamagnetic.
The metal complex ion that is paramagnetic is ______.
(Atomic number of Fe = 26, Cu = 29, Co = 27 and Ni = 28)
