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Assertion (A): Magnetic field never intersects each other. Reason (R): If two magnetic field lines intersect, it would imply two different directions of the magnetic field at that point.
ANSWER: [A] Explanation: Assertion (A) states that magnetic field lines never intersect, which is true. Reason (R) correctly explains this, as intersection would mean two directions of the magnetic field at one point, which is impossible. Hence, both A and R are true, and R is the correct explanatioRead more
ANSWER: [A]
Explanation: Assertion (A) states that magnetic field lines never intersect, which is true. Reason (R) correctly explains this, as intersection would mean two directions of the magnetic field at one point, which is impossible. Hence, both A and R are true, and R is the correct explanation of A.
See lessRenuka was studying a diagram related to a defect of vision and noted down possible causes for it. She wrote the following statements in her notebook. I. The focal length of the eye lens is too long. II. The eye ball becomes too small. III. The focal length of the eye lens is too short. IV. The eye ball becomes too long. Based on the given diagram, choose to the correct option that lists the correct causes of this defect.
The diagram shows myopia (nearsightedness), where the image forms in front of the retina. This defect occurs when the focal length of the eye lens is too short (III) or the eyeball becomes too long (IV). Hence, the correct option is (d) III and IV.
The diagram shows myopia (nearsightedness), where the image forms in front of the retina. This defect occurs when the focal length of the eye lens is too short (III) or the eyeball becomes too long (IV). Hence, the correct option is (d) III and IV.
See lessAn optical device ‘X’ is placed obliquely in the path of a narrow parallel beam of light. If the emergent beam gets displaced laterally, the device ‘X’ is:
When a narrow parallel beam of light passes through an optical device and emerges displaced laterally but parallel to itself, the device must be a glass slab. A plane mirror reflects without displacement, a convex lens converges or diverges light, and a prism deviates light angularly. Hence, the corRead more
When a narrow parallel beam of light passes through an optical device and emerges displaced laterally but parallel to itself, the device must be a glass slab. A plane mirror reflects without displacement, a convex lens converges or diverges light, and a prism deviates light angularly. Hence, the correct answer is (c) glass slab, which produces lateral displacement without altering the beam’s direction of propagation.
See lessThe electronic configuration of elements X (2, 4) and Y (2, 8, 1) is given. Based on the information given above, answer the following questions: (a) Which type of bond is formed between X and Y? Explain with reason. (b) How many valence electrons take part in the bond formation between X and Y? Explain. (c) Give the chemical formula of the compound. (d) State one physical property of this compound based on the type of bonding. (e) Write the chemical equation for the reaction of Y with ethanoic acid.
(a) The bond formed between X and Y is a covalent bond, because element X (carbon) shares its valence electrons with element Y (hydrogen - like or sodium) to achieve a stable configuration. (b) Four valence electrons from X and one valence electron from Y participate in bond formation, as X needs toRead more
(a) The bond formed between X and Y is a covalent bond, because element X (carbon) shares its valence electrons with element Y (hydrogen – like or sodium) to achieve a stable configuration.
(b) Four valence electrons from X and one valence electron from Y participate in bond formation, as X needs to share electrons to complete its octet.
(c) The chemical formula of the compound is , as X forms four single bonds with four Y atoms.
(d) The compound is generally a poor conductor of electricity because covalent compounds do not have free ions or electrons to conduct current.
(e) When element Y (like Na) reacts with ethanoic acid , hydrogen gas is evolved, and the salt sodium ethanoate is formed.
CH3COOH + Na → CH3COONa + H2 ↑
See lessObserve the following diagram showing the conditions under which a metal ‘M’ corrodes. List your observations in each of the three cases A, B and C with the reason, if the metal ‘M’ is generally protected against corrosion by the method of galvanisation.
Case A: Significant corrosion will be observed on the metal surface because the protective zinc coating on the metal readily react with oxygen and the moisture present in the moist air. Case B: No corrosion will be observed due to the oil layer with reacts with acts as a barrier and effectively inhiRead more
Case A: Significant corrosion will be observed on the metal surface because the protective zinc coating on the metal readily react with oxygen and the moisture present in the moist air.
Case B: No corrosion will be observed due to the oil layer with reacts with acts as a barrier and effectively inhibiting corrosion.
Case C: Minimal to no corrosion will be observed due to lack of moisture in the presence of dry air.
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