CBSE Class 12 Mechanical Engineering Question Paper 2016 with Answer Key (March 12)

CBSE CLASS XII Questions

• 1.

  Show that \( \mathbf{E} = \rho \mathbf{J} \) leads to Ohm's law. Write a condition in which Ohm's law is not valid for a material.

  View Solution

  ---

• 2.

  Why is a solution of Ni(H₂O)₆²⁺ green while a solution of Ni(CN)₄²⁻ is colourless? (At. No. of Ni = 28)

  View Solution

  ---

• 3.

  Draft an invitation card on behalf of the Principal of J.B. Bhatia Public School for the launch of ‘Yoga for Life’ programme in the school. Mention a compelling highlight of the programme along with other necessary details.
  

  View Solution

  ---

• 4.

  Answer the following questions:

  [(i)] Explain the structure of a mature embryo sac of a typical flowering plant.

  [(ii)] How is triple fusion achieved in these plants?

  OR

  [(i)] Describe the changes in the ovary and the uterus as induced by the changes in the level of pituitary and ovarian hormones during menstrual cycle in a human female.

  View Solution

  ---

• 5.

  Flowering plants with hermaphrodite flowers have developed many reproductive strategies to ensure cross-pollination. Study the given outbreeding devices adopted by certain flowering plants and answer the questions that follow.
  
  Note : All plants belong to the same species. No pollen tube growth/inhibition of pollen germination on stigma. Pollen germination on stigma.

  • [(a)] Name and define the outbreeding device described in the above table.
  • [(b)] Explain what would have been the disadvantage to the plant in the absence of the given strategy.

  View Solution

  ---

• 6.

  While doing qualitative analysis in chemistry lab, Abhishek added yellow coloured potassium chromate solution into a test tube. He was surprised to see the colour of the solution changing immediately to orange. He realised that the test tube was not clean and contained a few drops of some liquid. Which of the following substances will be the most likely liquid to be present in the test tube before adding potassium chromate solution?

  • Sodium hydrogen carbonate solution
  • Methyl orange solution
  • Sodium hydroxide solution
  • HCl solution
  View Solution