State two ways to prevent the rusting of iron.
Solution and Explanation
Two ways to prevent the rusting of iron are:
- Oiling, greasing, or painting: By applying oil, grease, or paint, the surface becomes water proof and the moisture and oxygen present in the air cannot come into direct contact with iron. Hence, rusting is prevented.
- Galvanisation: An iron article is coated with a layer of zinc metal, which prevents the iron to come in contact with oxygen and moisture. Hence, rusting is prevented.
Top Questions on Corrosion
The figure shows a rod PQ, hinged at P, rotating counter-clockwise with a uniform angular speed of 15 rad/s. A block R translates along a slot cut out in rod PQ. At the instant shown the distance \( PR = 0.5 \, {m} \) and \( \theta = 60^\circ \). The relative velocity of R with respect to the rod PQ is 5 m/s at the instant shown. The relative acceleration of R with respect to the rod PQ is zero at the instant shown.
Which one of the following is the CORRECT magnitude of the absolute acceleration (in m/s\(^2\)) of block R?
Consider two blocks, P of mass 100 kg and Q of mass 150 kg, resting as shown in the figure. The angle \( \theta = 30^\circ \). The coefficient of friction between the two blocks is 0.2. Assume no friction exists at all other interfaces. The minimum force required to move the block P upward is \( W \). Which one of the following options is closest to the CORRECT magnitude of \( W \) (in N)?
A force of \( P = 100 \, {N} \) is applied at the ends of the pliers as shown in the figure. Neglecting friction, the force exerted by the upper jaw on the workpiece is ........... N (in integer).
- For a certain linear elastic isotropic material, the Young’s modulus is 140 GPa and the shear modulus is 50 GPa. The Poisson’s ratio for the material is ........... (rounded off to two decimal places).
Consider a beam with a square box cross-section as shown in the figure. The outer square has a length of 10 mm. The thickness of the section is 1 mm. The area moment of inertia about the x-axis is ........... mm\(^4\) (in integer).
Questions Asked in CBSE X exam
- Show the formation of magnesium chloride by electron transfer. Write the name of the cation and anion present in the compound formed. (Atomic Number of Mg = 12, Cl = 17)
- CBSE Class X - 2025
- Chemical bonding and molecular structure
प्रादेशिक स्तर पर आयोजित होने वाली 100 मीटर की बाधा दौड़ में आपके मित्र को प्रथम स्थान मिला है। उसे बधाई देते हुए लगभग 40 शब्दों में एक संदेश लिखिए।
- CBSE Class X - 2025
- पत्र लेखन
Select TRUE statements about lymph from the following:
A. Lymph vessels carry lymph through the body and finally open into larger arteries.
B. Lymph contains some amount of plasma, proteins and blood cells.
C. Lymph contains some amount of plasma, proteins and red blood cells.
D. Lymph vessels carry lymph through the body and finally open into larger veins.
The true statements are:- CBSE Class X - 2025
- Circulatory System
- Two statements are given below. They are Assertion (A) and Reason (R). Read both the statements and choose the correct option:
Assertion (A): The French speaking community was rich in comparison to the Dutch speaking community in Belgium.
Reason (R): Dutch speaking community got the benefit of economic development and education much later.- CBSE Class X - 2025
- Power Sharing
- According to a popular quote – “Kindness is stronger than iron bars.”
Anil did not hand the thief over to the police. In what way did Anil’s act of wisdom and forgiveness transform Hari Singh?
(The Thief’s Story)- CBSE Class X - 2025
- Indian English Literature/Prose