I. When ethanol burns in air or oxygen, it reacts vigorously and is completely oxidised to form carbon dioxide and water, releasing heat and light energy in the form of a flame. II. When ethanol is heated strongly with excess concentrated sulphuric acid, a water molecule is removed from each ethanolRead more
I. When ethanol burns in air or oxygen, it reacts vigorously and is completely oxidised to form carbon dioxide and water, releasing heat and light energy in the form of a flame.
II. When ethanol is heated strongly with excess concentrated sulphuric acid, a water molecule is removed from each ethanol molecule and ethene (an unsaturated hydrocarbon) is formed; this is called dehydration.
III. When ethanol is treated with acidified potassium dichromate, it undergoes oxidation: the alcohol is converted into ethanoic acid (acetic acid) while the oxidising agent is reduced.
Yes, the CBSE 2026 tentative date sheet for Classes 10 and 12 has been released on the official CBSE website. It provides students, parents, and schools with a clear outline of the proposed examination schedule well in advance, helping them plan their studies systematically. However, it is importantRead more
Yes, the CBSE 2026 tentative date sheet for Classes 10 and 12 has been released on the official CBSE website. It provides students, parents, and schools with a clear outline of the proposed examination schedule well in advance, helping them plan their studies systematically. However, it is important to note that this is only a tentative timetable and may undergo changes before the final version is announced. Students are advised to regularly check the official website, for updates and follow the latest notifications to ensure proper preparation and time management for their board examinations.
The tentative CBSE 2026 board exams are scheduled to begin on 17 February 2026. They may extend all the way until 15 July 2026 (covering main, supplementary, and special exams)
ANSWER: [A] Explanation: The correct answer is [A] (ii) and (iv). During inhalation, the diaphragm flattens and the chest cavity becomes larger, allowing air to enter the lungs. Residual volume never decreases, and the diaphragm is raised only during exhalation.
ANSWER: [A]
Explanation: The correct answer is [A] (ii) and (iv). During inhalation, the diaphragm flattens and the chest cavity becomes larger, allowing air to enter the lungs. Residual volume never decreases, and the diaphragm is raised only during exhalation.
ANSWER: [A] Explanation: The correct answer is [A] Fore brain. The forebrain (cerebrum) is called the “thinking part” of the brain. It controls intelligence, reasoning, learning, memory, emotions, and voluntary actions. Midbrain and hindbrain mainly control reflexes, balance, and involuntary activitRead more
ANSWER: [A]
Explanation: The correct answer is [A] Fore brain. The forebrain (cerebrum) is called the “thinking part” of the brain. It controls intelligence, reasoning, learning, memory, emotions, and voluntary actions. Midbrain and hindbrain mainly control reflexes, balance, and involuntary activities.
ANSWER: [A] Explanation: The correct answer is [A] Oestrogen. Oestrogen, secreted by the ovaries, regulates the menstrual cycle and development of female reproductive organs. Deficiency of oestrogen often causes irregular menstrual cycles. Testosterone is male hormone, while adrenalin and thyroxin aRead more
ANSWER: [A]
Explanation: The correct answer is [A] Oestrogen. Oestrogen, secreted by the ovaries, regulates the menstrual cycle and development of female reproductive organs. Deficiency of oestrogen often causes irregular menstrual cycles. Testosterone is male hormone, while adrenalin and thyroxin are unrelated to menstruation.
Write chemical equation to show what happens when ethanol: (I) burns in oxygen/air. (II) is heated at 443 K in excess conc. sulphuric acid. (III) reacts with acidified potassium dichromate.
I. When ethanol burns in air or oxygen, it reacts vigorously and is completely oxidised to form carbon dioxide and water, releasing heat and light energy in the form of a flame. II. When ethanol is heated strongly with excess concentrated sulphuric acid, a water molecule is removed from each ethanolRead more
I. When ethanol burns in air or oxygen, it reacts vigorously and is completely oxidised to form carbon dioxide and water, releasing heat and light energy in the form of a flame.
II. When ethanol is heated strongly with excess concentrated sulphuric acid, a water molecule is removed from each ethanol molecule and ethene (an unsaturated hydrocarbon) is formed; this is called dehydration.
III. When ethanol is treated with acidified potassium dichromate, it undergoes oxidation: the alcohol is converted into ethanoic acid (acetic acid) while the oxidising agent is reduced.
See lessIs the CBSE 2026 date sheet released?
Yes, the CBSE 2026 tentative date sheet for Classes 10 and 12 has been released on the official CBSE website. It provides students, parents, and schools with a clear outline of the proposed examination schedule well in advance, helping them plan their studies systematically. However, it is importantRead more
Yes, the CBSE 2026 tentative date sheet for Classes 10 and 12 has been released on the official CBSE website. It provides students, parents, and schools with a clear outline of the proposed examination schedule well in advance, helping them plan their studies systematically. However, it is important to note that this is only a tentative timetable and may undergo changes before the final version is announced. Students are advised to regularly check the official website, for updates and follow the latest notifications to ensure proper preparation and time management for their board examinations.
The tentative CBSE 2026 board exams are scheduled to begin on 17 February 2026. They may extend all the way until 15 July 2026 (covering main, supplementary, and special exams)
See lessWhich of the following statements are correct in reference to the role of A (shown in the given diagram) during a breathing cycle in human beings? (i) It helps to decrease the residual volume of air in lungs. (ii) It flattens as we inhale. (iii) It gets raised as we inhale. (iv) It helps the chest cavity to become larger.
ANSWER: [A] Explanation: The correct answer is [A] (ii) and (iv). During inhalation, the diaphragm flattens and the chest cavity becomes larger, allowing air to enter the lungs. Residual volume never decreases, and the diaphragm is raised only during exhalation.
ANSWER: [A]
Explanation: The correct answer is [A] (ii) and (iv). During inhalation, the diaphragm flattens and the chest cavity becomes larger, allowing air to enter the lungs. Residual volume never decreases, and the diaphragm is raised only during exhalation.
See lessWhich out of the three parts of the brain is known as the thinking part?
ANSWER: [A] Explanation: The correct answer is [A] Fore brain. The forebrain (cerebrum) is called the “thinking part” of the brain. It controls intelligence, reasoning, learning, memory, emotions, and voluntary actions. Midbrain and hindbrain mainly control reflexes, balance, and involuntary activitRead more
ANSWER: [A]
Explanation: The correct answer is [A] Fore brain. The forebrain (cerebrum) is called the “thinking part” of the brain. It controls intelligence, reasoning, learning, memory, emotions, and voluntary actions. Midbrain and hindbrain mainly control reflexes, balance, and involuntary activities.
See lessA female is suffering from irregular menstrual cycle. The doctor prescribed her some hormonal tablets. Which option shows the hormones she lacks in her body from the endocrine gland?
ANSWER: [A] Explanation: The correct answer is [A] Oestrogen. Oestrogen, secreted by the ovaries, regulates the menstrual cycle and development of female reproductive organs. Deficiency of oestrogen often causes irregular menstrual cycles. Testosterone is male hormone, while adrenalin and thyroxin aRead more
ANSWER: [A]
Explanation: The correct answer is [A] Oestrogen. Oestrogen, secreted by the ovaries, regulates the menstrual cycle and development of female reproductive organs. Deficiency of oestrogen often causes irregular menstrual cycles. Testosterone is male hormone, while adrenalin and thyroxin are unrelated to menstruation.
See less