# Practice paper for AHSEC class 12 of 2020

Total mark -36

Total time -90 minutes

Each question carries carries 3 marks

Q1- Obtain the relation between angle of minimum deviation for a prism and its refractive index .

Q2- Draw the ray diagram for reflecting type telescope . Write down advantages of reflecting type telescope over refracting type telescope .

Q3- define critical angle  . Write down the condition for total internal reflection .What is optical fibre .

Q4-Write down Huygens principles . Draw the diagram for wavefront  due to a point source.

Q5- Prove that for destructive interference path difference between the two light waves should be odd integral multiple of λ/ 2.

Q6- State Malus law . Prove that when light is incident at polarising angle on a reflecting surface angle between reflected and refracted light is 90 º

Q7- Draw a ray diagram for Davission and Germer  experiment . Write down few uses of de Broglie’s hypothesis.

Q8- State Bohr’s postulate  . Write down its failures .

Q9- Draw and explain binding energy curve.

Q10-  Explain the working of zener diode as voltage regulator

Q11- Give the Boolean expression and truth table of NAND gate . How OR gate can be obtained from NOR gate and NAND gate ?

Q12- Define the following terms :-  noise , attenuation and modulation .