CBSE Class 12 Physics Question Paper 2018 with Answer Key (March 7, Set 1 - 55/1)

CBSE CLASS XII Questions

• 1.

  परसेवा का आनंद — 120 शब्दों में रचनात्मक लेख लिखिए:

  View Solution

  ---

• 2.

  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

  ---

• 3.

  Write vector form of Biot–Savart law.

  View Solution

  ---

• 4.

  In his experiment on photoelectric effect, Robert A. Millikan found the slope of the cut-off voltage versus frequency of incident light plot to be \( 4.12 \times 10^{-15} \, \text{Vs} \). Calculate the value of Planck’s constant from it.

  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.

  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