Physics 12th Class
Fill in the Blanks
Five Year Papers
1. If a liquid contracts on freezing, an increase of pressure ______the freezing point.
2. The flux through a surface is maximum, when the angle between E and A is ______.
3. An electron volt = ______joules.
4. Uit of Electric intensity in S.I system is ______.
5. ______is the unit of mutual-inductance.
6. Back e.m.f is the effect of self-inductance in a coil when ______current passes.
7. From the theory of relativity the velocity of light is a ______constant and is equal to ______m/s.
8. The amount of heat, which is absorbed during the change of state without the rise in temperature, is known as ______.
9. If heat energy is removed from the system, the change in entropy is ______.
10. The flux through a closed surface, which does not contain any charge, is ______.
11. The electric field at any point between two oppositely charged plain sheet is ______.
12. ______is the unit of physical quantity, Magnetic Induction B.
13. If a one-metre long wire is placed perpendicularly in a magnetic field of value 5mT, the force it experiences is equal to 5N.
14. The value of the permitivity of free space is given by ______.
15. The minimum energy required to excite a hydrogen atom is ______.
16. During the change of state, the heat supplied does not change the temperature. It is used in ______.
17. The flux through a surface is maximum when the angle between E and DA is ______.
18. The resistivity of a material of a conductor increases due to increase in ______.
19. Back e.m.f is the effect of self-inductance in a coil when a ______current passes through it.
20. The frequency of the incident light at which the photons have energy equal to the work function of a metal is called the ______of that metal.
21. When temperature of source and sink of a heat engine becomes equal, the entropy change will be ______.
22. Quantity of heat in a body depends upon its mass temperature and ______.
23. Electric flux through any closed surface due to point charges enclosed in it is equal to ______.
24. The ______in the free electron is responsible for generation of current in the wire.
25. Units of electrical energy commonly used is ______.
26. A balanced ______is used to determine an unknown resistance.
27. Nuclei of same element with different nuclear masses but the same charge number are called ______.
28. Radiations with wavelength greter than red light are called ______radiations.
29. The galvanometer can be made sensitive if the value of the factor C/BNA is ______.
30. A particle with mass equal to an electron but charge that of proton is called ______.
Chapter 11
Heat
1. Mathematically Boyle’s Law is stated as ______.
2. Mathematically Charle’s Law is stated as ______.
3. Absolute Zero of the temperature is ______.
4. The gas in which the molecules exert no force on each other is called ______.
5. In an ideal gas the molecules have ______.
6. Most of the gases with low density and well above the liquefication temperature behave as ______.
7. “At constant pressure and temperature the number of kilomoles of any gas is proportional to the volume of the gas.” This is called ______.
8. General gas law is mathematically stated as ______.
9. General gas law or general gas equation is derived from ______, ______, and ______.
10. The value of universal gas constant R is given by ______.
11. The pressure of an ideal gas is given by the following equation ______.
12. In terms of average kinetic energy of the molecules of the gas, the pressure of an ideal gas is given as ______.
13. “Equal volumes of gases at the same temperature and pressure contain equal number of molecules.” This is called ______.
14. The change in length per unit length per Kelvin rise in temperature is called ______.
15. Mathematically co-efficient linear expansion is written as ______.
16. Coefficient of cubical expansion in terms of co-efficient of linear expansion is written as ______.
17. The amount of heat required to raise the temperature of 1.0kg of a substance through 1k is called ______.
18. The study of relationship between heat and other forms of energy is called ______.
19. Any object or set of objects that we wish to consider is called ______.
20. Every thing other than the system is termed as ______.
21. A system in which the mass of the system remains constant is called a ______.
22. The variables like p, V and t are called ______.
23. The process in which the state variables acquire the same values at all stages of the process independent of the direction in which the process is being carried out is called ______.
24. A cyclic process is that in which during each cycle, it extracts heat from a heat reservoir maintained at one temperature, converts part of this energy to useful work and rejects the remainder to a heat reservoir at a lower temperature is called ______.
25. The ratio of net output work per cycle to input energy per cycle is called ______.
26. A cycle that has highest possible efficiency is called ______.
27. Efficiency of a Carnot Engine is defined as ______.
28. “Heat flows spontaneously from a hotter to a colder body, but not the other way round.” This is called ______.
29. “It is impossible for a cyclic system to transfer heat from body at a low temperature to a body at a higher temperature unles external work is done on system." This is ______.
30. It is impossible to construct an engine, operating continuously in a cycle, which does nothing other than to take heat from a source and perform an equivalent amount of work without having a sink.” This is ______.
31. A heat engine operating in reverse is called ______.
32. A device, which causes heat to flow from a low temperature reservoir to a high temperature reservoir, is called ______.
33. Coefficient of performance of refrigerator is ______.
34. Measure of disorder is called ______.
35. The change in entropy is ______.
36. Second law of th4ermodynamics can be restated in terms of entropy as ______.
Chapter 12
Electrostatics
1. Mathematically coulomb’s Law of electrostatic is stated as F = ______.
2. The value of Coulomb’s constant k is given as ______.
3. The value of coulomb’s constant k in terms of permitivity of free space is given as ______.
4. The value of permitivity of free space is ______.
5. The unit of charge in SI system is ______.
6. One coulomb is that quantity of charge which when placed one metre from an identical charge in vacuum (or air) repels with a force equal to ______.
7. Coulomb’s force in the medium of relative permitivity Îr is given as ______.
8. 1 mC = ______.
9. 1pC = ______.
10. The space around any charge in which its influence could be felt by another charge placed there is called ______.
11. Electric field intensity E at any point surrounding the charge q is defined as ______.
12. If E represents electric field intensity and qo a point charge, then mathematically electric field intensity is defined as ______.
13. The electric field intensity at a point in an electric field is defined as ______.
14. The potential at a point, a distance r from a charge q is ______.
15. 1 volt = ______.
16. The quantity DV/DR is called ______.
17. The unit of electric intensity E, N/C is equivalent to ______.
18. The amount of energy acquired or lost by an electron when it is displaced across two points between which the potential difference is one volt is called ______.
19. 1eV = ______.
20. A device, which is used to store electric charge, is called ______.
21. The ratio Q/V is called ______.
22. The unit of capacitance is ______.
23. 1 farad = ______.
24. 1 micro farad = ______.
25. 1 pico farad = ______.
Chapter 13
Current Electricity
1. If A is the area of cross-section of a conductor and L is the length of the conductor, then resistivity “r” of a conductor is given by the relation ______.
2. The unit of resistivity is ______.
3. Resistance ‘R’ of a wire of length ‘L’, cross-section area ‘A’ and resistivity ‘r’ is given by the relation ______.
4. If same current passes through all the resistance and the resistors provide a simple path to the flow of the current, then they are said to be connected in ______.
5. If two or more resistors are joined such a way that one end of each resistor is connected to one terminal of the battery while the other ends are connected to the second terminal of the battery, they they are said to be connected in ______.
6. If resistors R1, R2, R3 ….R4 are connected in series then the resultant equivalent resistance Re is given by ______.
7. If resistors R1, R2, R3 ….R4 are connected in parallel then the resultant equivalent resistance Re is given by ______.
8. Resultant resistance of the resistors joined in parallel is ______than the least resistance of the component resistors.
9. As the charge flows through the conductor energy is dissipitated in the form of ______.
10. Mathematically power dissipitated is defined as ______.
11. Power dissipated is also defined as ______.
12. Power dissipated is also defined as ______.
13. Power dissipated is also defined as ______.
14. The unit of power ______.
15. 1 watt = ______.
16. The practical unit of power in common use is ______.
17. The amount of energy delivered by the current in one hour when it supplies energy at the rate of 100 J/s is called ______.
18. 1 kwh = ______.
Chapter 14
Magnetism and Electromagnetism
1. The magnitude of the magnetic force F on the wire of length ‘l’ carrying current I is given by ______.
2. The force exerted on a wire of length one metre carrying one ampere current placed at right angle to the field is called ______.
3. Mathematically magnetic induction is defined as ______.
4. The S.I unit of magnetic induction is ______.
5. Gauss’s (G) is a unit of ______.
6. 1T(Tesla) = ______G.
7. Torque on a current carrying rectangular loop of area A and having N turns and placed in a magnetic field B is given by the relation ______.
8. The total number of lines of magnetic induction passing through a surface placed perpendicular to the magnetic field is called ______.
9. Mathematically magnetic flux is defined as ______.
10. Magnetic flux f, through certain area A is maximum if the angle between the magnetic field B and area A is ______.
11. Magnetic flux f, though certain area A is zero if the angle between the magnetic field B and area A is ______.
12. The SI unit of magnetic induction is ______.
13. Nm/A is commonly called ______.
14. 1 Wb/m2 is known as ______.
15. The magnetic field B is also called ______.
16. The force on a charged particle of charge ‘q’ moving with velocity ’v’ in a magnetic field of strength ‘B’ is given by ______.
17. An electron travelling with a velocity v describes a circular path when it enters a uniform magnetic field such that ______.
18. Ampere’s law is analogous to ______.
19. The dot product of B and I around any closed path equals to moI, where I is the total steady current threaded by the path. This is called ______.
20. Mathematically, Ampere’s law can be written as ______.
21. The value of permeability of free space mo is ______.
22. By winding wire in a helix around a cylindrical surface, we will get ______.
23. If there are n turns per unit length of the solenoid and each turn carries a current I, then the magnetic field B of a solenoid is given by ______.
24. A solenoid that has been bent into a circle is called ______.
25. The magnetic field of a toroid is given by ______.
26. The current produced by moving the loop by wire across a magnetic field is called ______.
27. The product of induced current and resistance of the wire i.e. I x r gives ______.
28. The generation of induced emf in a circuit is known as ______.
29. When the magnetic flux changes through a loop on a coil, an induced emf is produced in it. This is called ______.
30. An induced emf always drives a current whose magnetic field opposes the original change in flux. This is called ______.
31. Mathematically Faraday’s law of electromagnetic induction is defined by the relation ______.
32. “The direction of an induced current is such as to oppose the cause producing it.” This is called ______.
33. Mathematically mutual inductance is written as ______.
34. Mutual inductance is measured in ______.
35. Vs/A is known as ______.
36. If the current changing at the rate of one ampere per second in the primary causes an induced emf of one volt in the secondary, then the mutual inductance of the two coils is said to be ______.
37. In the relation emf = , L is called ______.
38. The emf linked with the same coil when the rate of change of current in the coil is unity, is called ______.
39. Non-inductive resistances are used in ______.
40. The induced emf generated as a result of the motion of the wire through the magnetic field is called ______.
41. If v is the velocity with which the wire is dragged, I is the length of the wire and B is the magnetic field, then motion emf is written as ______.