+2 Physics

How was your Physics Practical Examination?

Hello students!

It’s the time of AISSCE Practical Examination.

How was your Physics Practical Examination and Viva?

Which questions were asked to you?

Which were the experiments and activities you were asked to perform?

How farely did you do it?

Share your experience here as comments to this post. Your responses will be a boon for the others.

You can post the questions you were asked during Viva so that others can find the answers to them and learn for the Viva during their turn.

Random collection of Physics Viva Questions

1. State the Principle of a potentiometer. (The students say that potential drop is proportional to length but the constant quantities are not mentioned)
2. How can we increase the sensitivity of a potentiometer?
3. Define figure of merit of a galvanometer.
4. Which has more resistance – a galvanometer or a milliammeter?
5. How does an LED emit light?
6. What is the difference between an ordinary diode and an LED?
7. Define principal axis of a convex lens?
8. What happens to the focal length of a concave mirror if it is immersed in water?
9. What are the factors affecting the internal resistance of a cell?
10. What are the difference between primary and secondary cell?
11. Why can’t we use a dry cell for starting a car?
12. What happens to the resistivity of a wire when it is doublefolded?
13. How does the resistance of a wire depend on its dimensions?
14. Why are the resistances used in a resistance box is like 1,2,2,5,10,20,20,50,100,200,200,500,1000,2000,2000,5000 etc?
15. Why constantan or manganin wires are used for making the resistance coils in resistance box?
16. What is a standard resistance?
17. What are the characteristics of a standard resistance?
18. What are the precautions to be observed while doing electricity experiments in general?
19. What is a galvanometer?
20. What is the resistance of an ideal ammeter?
21. Why is ammeter always connected in series and voltmeter always connected in parallel?
22. How can we convert a galvanometer into an ammeter or a voltmeter?
23. What is shunt?
24. What is AVO meter?
25. What is the effect of temperature on the resistance of a conductor?
26. Why does the resistance of a conductor increases with temperature, whereas that of a semiconductor decreases with temperature.
27. What is conductance?
28. What are non ohmic devices? give an example.
29. What are superconductors?
30. Define emf
31. Why emf is said to be a misnomer?
32. What happens if the battery used in the primary circuit of a potentiometer has less emf compared to the emf of the cell used in the secondary circuit?
33. If you find that the galvanometer reading is shaky, what error can you expect?
34. What do you mean by figure of merit of a galvanometer?
35. Why a moving coil galvanometer is called so?
36. What is the principle of a galvanometer?

CLASS XI PHYSICS IMPORTANT QUESTIONS

3 MARKS:
1) DISTINGUISH BETWEEN FUNDAMENTAL UNITS AND DERIVED UNITS.
2) WHAT ARE THE TWO TYPES OF COLLISION? EXPLAIN THEM.
3) STATE NEWTONS FIRST LAW OF MOTION.
4) TWO EQUAL FORCES ARE ACTING AT A PIONT WITH AN ANGLE OF 60 BETWEEN THEM. IF THE RESULTANT FORCE IS EQUAL TO 20√3N. FIND THE MAGNITUDE OF EACH FORCE.
5) WHAT ARE THE DIFFERENT TYPES OF EQUILIBIRIUM.
6) STATE THE UNIVERSAL LAW OF GRAVITATION.
7) DEFINE GRAVITATIONAL POTENTIAL.
8) WHAT IS REYNOLD’S NUMBER?
9) WHAT IS SURFACE TENTION?
10) DEFINE SIMPLE HARMONIC MOTION.
11) WHAT ARE DEGREES OF FREEDOM?
12) DEFINE SOLAR CONSTANT.

13) DEFINE POWER OF A LENS. WHAT ITS UNIT?
14) STATE TANGENT LAW.
15) WHAT IS THE DISTANE TRAVELLED BY SOUND IN AIR WHEN A TUNING FORK OF FREQUENCY 256HZ COMPLETES 25 VIBRATIONS? (THE SPEED OF SOUND IN AIR IS 343MS-I)

5 MARK:

1. WRITE ANY 5 RULES AND CONVENTIONS OF WRITING SI UNITS.
2. THE HORIZONTAL RANGE OF A PROJECTILE ID 4√3 TIMES ITS MAXIMUM HEIGHT. FIND THE ANGLE OF PROJECTION.
3. STATE THE LAW OF CONSERVATION OF ANGULAR MOMENTEM AND EXPLAIN IT WITH AN EXAMPLE.
4. STATE KEPLER’S LAW OF PLENTARY MOTION.
5. GIVE THE GRAPHICAL REPRESENTATION OF i)DISPLACEMENT ii) VELOCITY iii) ACCELERATION OF A PARTICLE EXUCUTING SHM. MENTION THE DIFFERENCES BETWEEN THEM.
6. What are the characteristics of progressive waves?
7. List out any 5 postulates of kinetic theory of gases.

10 MARK:

1. State and prove parallelogram law of vectors and discuss the special cases.
2. State and prove bernoulli’s theorem.
3. Derive Meyer’s relation.
4. Describe the working of angstrom pyrheliometer with diagram. (NOT FOR CBSE)

SEMICONDUCTOR DEVICES–CLASS 12 PHYSICS QUESTION BANK

1. Draw a circuit diagram of OR gate.

2. What is a logic gate?

3. What types of charge-carriers are there in a n-type semi conductor?

4. Give the logical symbol of an AND gate. Mark the inputs and outputs.

5. Draw the logic symbol for a NAND gate.

6. Which biasing will make the resistance of p-n junction high?

7. Write the truth table for OR gate.

8. What is the change in the collector current, in a transistor of a.c. current gain 150, for a 100µA change in its base current?

9. When the voltage drop across a p-n junction diode is increased from 0.65V to 0.70V, the change in the diode current is 5mA. What is the dynamic resistance of the diode?

10. How does conductivity of a semiconductor change with rise in its temperature? Read more…

Class 12 Physics : Electrostatics Revision Test

Max marks:50 Time:2hrs

1. A glass rod rubbed with silk acquires a charge of 6×10^-12 C. Calculate the number of electrons it has gained or lost. (1)
2. If the magnitude of each charge becomes doubled, the separation between them is halved and the system of charges kept in a medium of=3 Calculate the force between them. (1)
3. If two equal charges separated by a distance of 2m in air medium experiences a force of 0.9×10¹⁰ C, Calculate the magnitude of each charge. (1)
4. Electric field intensity is 400Vm^-1 at a distance of 2 m from a point charge. At what distance it will become 100 Vm^-1? (1)
5. What will be the force experienced by a particle of charge 2µC placed in an electric field of 10kVm^-1? (1)
6. What is the work done by moving 400μF charge between two points separated by a distance of 27 cm on an equipotential surface? (1)
7. Calculate the number of electric lines of force from a charge 1.7708X10^-6 C in air medium? (1)
8. Two protons ‘A’ and ‘B’ are placed between two parallel plates having a potential difference ‘V’ as shown in the figure. Will these protons experience equal or unequal force? (1)
9. Draw an equipotential surface for a point charge q> 0(1)
10. The capacitance of a parallel plate capacitor is ‘C’. If 15 such capacitors are connected in series and then in parallel, what is the ratio of effective capacitance of first case to the second? (1)
11. What is electric polarization ,polar and non polar molecules?( 2)
12. 2) Define electrostatic induction and corona discharge. ( 2)
13. Calculate the ratio of force experienced by a proton to that of the electron placed in an electric field of 4KVm^-1. ( 2)
14. If an electrician has three capacitors of capacitances 4µF, 7µF& 12µF. How should he connect them, So that the effective capacitance will be 10µF? ( 2)
15. Define the SI unit of potential difference and charge. ( 2)
16. Two charges of 20µC and -20µC are placed 20 cm apart at points A and B respectively. Compute the electric field strength at point C, 20 cm away from both A and B.(3)
17. Three capacitors of capacitances 4µF, 6µF and 8µF are connected parallel to each other and the combination is connected across a battery of 25V. Calculate the charges present on each capacitor and the total charge flows from the source. (3)
18. Derive an expression for the torque experienced by a dipole in an external electric field. (3)
19. Obtain an expression for the capacitance of a parallel plate capacitor. (3)
20. Derive the relation E= (3)
21. Derive an expression for the potential at a point due to dipole. Write the special cases also.(5)
22. Derive an expression for ‘E’ at a point on the axial line of the dipole. (5)
23. Explain with a neat diagram the principle, construction and working of a Van de Graff generator. (5)

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Which way is better for giving AIEEE exam? ONLINE or OFFLINE.

Which way is better for giving AIEEE exam? ONLINE or OFFLINE.

-Yash asked -

Answer:

I would personally recommend online. But the choice is up to you.

Please follow the following check to decide. Try to identify for yourself the plus points and negative points of writing AIEEE online and OFFLINE.

The most important disadvantage of choosing the OFFLINE version is the rarity of choices. You may have to travel long if you are not nearby the centre.

The decision is yours. But, think well before you decide.

Does gravity travel instantaneously?

Does gravity travels instantaneously? Or it travels equal to the speed of light.

Answer:

No clear answer now. If we believe in the Theory of relativity, Gravity (Gravitational Waves travel with the same speed as that of light in vacuum. If gravitons are like photons, then it makes sense too.

However I invite you to think more and post your thoughts as comments here. Let the discussion begin.

I found the following links to know more

• http://metaresearch.org/cosmology/speed_of_gravity.asp
• http://en.wikipedia.org/wiki/Speed_of_gravity
• http://www.desy.de/user/projects/Physics/Relativity/GR/grav_speed.html