The assertion is incorrect because members of a homologous series differ by a fixed CH₂ unit and have similar functional groups and general formula. C₄H₁₀ is an alkane (saturated) with formula CnH2n+2, whereas C₄H₈ is an alkene and C₄H₆ an alkyne/diene — both unsaturated and belonging to different hRead more
The assertion is incorrect because members of a homologous series differ by a fixed CH₂ unit and have similar functional groups and general formula. C₄H₁₀ is an alkane (saturated) with formula CnH2n+2, whereas C₄H₈ is an alkene and C₄H₆ an alkyne/diene — both unsaturated and belonging to different homologous series. The reason statement R is true: the listed compounds (C₄H₈, C₄H₆, C₃H₄, C₃H₆, C₂H₄, C₂H₂) are examples of unsaturated hydrocarbons. Therefore, option D is the correct choice here.
(i) Defect: Myopia (nearsightedness) — image forms in front of the retina because the eye’s lens is too strong (focal length too short) or the eyeball is too long. (ii) Correction: use a concave (diverging) lens placed in front of the eye. It diverges incoming parallel rays so the eye’s lens then foRead more
(i) Defect: Myopia (nearsightedness) — image forms in front of the retina because the eye’s lens is too strong (focal length too short) or the eyeball is too long.
(ii) Correction: use a concave (diverging) lens placed in front of the eye. It diverges incoming parallel rays so the eye’s lens then focuses them on the retina.
(i) From the ray diagram, the image formed is real, inverted, and diminished because the object is placed beyond 2F₁ of a convex lens. (ii) The magnification will be –1 when the object is placed at 2F₁, as then the image is formed at 2F₂, real, inverted, and of the same size as the object.
(i) From the ray diagram, the image formed is real, inverted, and diminished because the object is placed beyond 2F₁ of a convex lens.
(ii) The magnification will be –1 when the object is placed at 2F₁, as then the image is formed at 2F₂, real, inverted, and of the same size as the object.
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.
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.
Assertion (A): C4H8, C4H6 and C4H10 are members of the same homologous series Reason (R): C4H8, C4H6, C3H4, C3H6, C2H4, C2H2 are unsaturated hydrocarbons.
The assertion is incorrect because members of a homologous series differ by a fixed CH₂ unit and have similar functional groups and general formula. C₄H₁₀ is an alkane (saturated) with formula CnH2n+2, whereas C₄H₈ is an alkene and C₄H₆ an alkyne/diene — both unsaturated and belonging to different hRead more
The assertion is incorrect because members of a homologous series differ by a fixed CH₂ unit and have similar functional groups and general formula. C₄H₁₀ is an alkane (saturated) with formula CnH2n+2, whereas C₄H₈ is an alkene and C₄H₆ an alkyne/diene — both unsaturated and belonging to different homologous series. The reason statement R is true: the listed compounds (C₄H₈, C₄H₆, C₃H₄, C₃H₆, C₂H₄, C₂H₂) are examples of unsaturated hydrocarbons. Therefore, option D is the correct choice here.
See lessStudy the diagram given below and answer the questions: (i) Name the defect of vision represented in the diagram. (ii) Redraw the diagram and show how a corrective lens resolves this defect? Label the lens type and focal point.
(i) Defect: Myopia (nearsightedness) — image forms in front of the retina because the eye’s lens is too strong (focal length too short) or the eyeball is too long. (ii) Correction: use a concave (diverging) lens placed in front of the eye. It diverges incoming parallel rays so the eye’s lens then foRead more
(i) Defect: Myopia (nearsightedness) — image forms in front of the retina because the eye’s lens is too strong (focal length too short) or the eyeball is too long.
(ii) Correction: use a concave (diverging) lens placed in front of the eye. It diverges incoming parallel rays so the eye’s lens then focuses them on the retina.
See lessStudy the ray diagram of an object placed in front of a lens. (i) Write three characteristics of the image formed? (ii) In which position of the object will the magnification be – 1?
(i) From the ray diagram, the image formed is real, inverted, and diminished because the object is placed beyond 2F₁ of a convex lens. (ii) The magnification will be –1 when the object is placed at 2F₁, as then the image is formed at 2F₂, real, inverted, and of the same size as the object.
(i) From the ray diagram, the image formed is real, inverted, and diminished because the object is placed beyond 2F₁ of a convex lens.
(ii) The magnification will be –1 when the object is placed at 2F₁, as then the image is formed at 2F₂, real, inverted, and of the same size as the object.
See lessAssertion (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 less