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#### Model 3 Mark Creative Questions (New Syllabus) 2020

12th Standard EM

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Physics

Time : 01:00:00 Hrs
Total Marks : 60

Part A

20 x 3 = 60
1. What happens when and electric dipole is held in a non-uniform electric field?

2. What is dielectrics or insulators.

3. How does one can understand the temperature dependence of resistivity of a conductor?

4. Find the expression for the equivalent emf & internal resistance of the series combination of cells

5. Mention the properties of Magnetic field lines?

6. In a certain region of space, electric field $\vec { E }$ and magnetic field $\vec { B }$ are perpendicular to each other. An electron enters in the region perpendicular to the direction of both $\vec { B }$ & $\vec { E }$ and moves undeflected. Find the velocity of electron.

7. Can a galvanometer be used for measuring the current? Explain.

8. What is Phasort and How to draw phasor diagram.

9. What is impedance? When does LCR circuit have minimum impedance?

10. Write the production of gamma rays and mention its properties and uses.

11. Name the parts of Electromagnetic spectrum which is
(i) used to destroy becteria.
(ii) produced by where is a sudden deceleration of high speed electrons.
(iii) used in food industry.

12. Write the difference between paraxial rays and marginal rays.

13. Use the lens equation to deduce algebraically the following:
"An object placed within the focus of a convex lens produces a virtual and enlarged image"

14. Write three characterists features in photoelectric effect which cannot be explained on the basis of wave theory of light, but can be explained only using Einstein's equation.

15. Two metals A and B have work functions 4 eV and 10 eV respectively. Which metal has the higher threshold wavelength?

16. Write the properties of neutrino?

17. Energy released per fission of a nucleus is of the order of 200 MeV whereas that per fusion, is of the order of 10 MeV. But a fusion bomb (Hydrogen bomb) is said to be more powerful than a fission bomb. Explain why?

18. Write the advantages of AM.

19. Explain why TV transmission towers made high.

20. Write the aim of artificial intelligence in robots.