Advertisements
Advertisements
Question
Pyrolusite ore is _______.
Options
MnO
MnO2
Mn2O7
Mn2O3
Advertisements
Solution
Pyrolusite ore is MnO2.
APPEARS IN
RELATED QUESTIONS
What is ferromagnetism?
What type of magnetism is shown in the following alignment of magnetic moments?
Define the following term:
Ferromagnetism
Write the type of magnetism observed when the magnetic moments are oppositely aligned and cancel out each other.
Write the type of magnetism observed when the magnetic moments are aligned in parallel and anti-parallel directions in unequal numbers.
Explain the following with suitable examples:
Paramagnetism
Give reasons:Ferrimagnetic substances show better magnetism than antiferromagnetic substances.
The complexion [Ni(CN)4]2- is:
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)
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
Example of ferromagnetic substance is ____________.
Substances that are strongly attracted by the applied magnetic field and can be permanently magnetized are ____________.
Which type of substances would make better permanent magnets?
Assertion: On heating ferromagnetic or ferrimagnetic substances, they become paramagnetic.
Reason: The electrons change their spin on heating.
Which of the following statements is not true?
A ferromagnetic substance becomes a permanent magnet when it is placed in a magnetic field becuase ______.
Which one of the following pairs has only paramagnetic species?
Which one of the following homo-diatomic molecule is paramagnetic?
The heat of combustion of a substance is:
Some of the polar crystals when heated produces small electrical current. This phenomenon is called ______.
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.
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:
Which one of the following compounds is diamagnetic and colourless?
