Question # 1

How can the power losses be minimized in a transformer?

Ans 1: The power can be minimized in transformer by implementing following considerations.
1. Core should be assembled from the laminated sheet of a material whose hysteresis loop are is very small.
2. The insulation between lamination sheets should be perfect so as to stop the flow of eddy current.
3. The resistance of the primary and secondary coils should be kept minimum.

Question # 2

How can the strain energy be determined from the force extension graph?

Ans 1: Strain energy can be determined from the force extension graph according to the following relation
Strain energy :1/2 l₁F₁

Question # 3

What are the difference between laser light and ordinary light?

Ans 1: The laser light is intense ,unidirectional and phase coherent ,so it does bit spread as compared to ordinary light.
The energy of laser can be focused at a point to get enough heat for welding which is not possible with ordinary light.
A laser beam is used as a surgical tool for welding detached retina which ordinary light can not do.

Question # 4

Differentiate between conventional and non-conventional current.

Ans 1: Conventional Current: The current flow die to positive charges from a point at higher potential to a point at lower potential is called conventional current.
Ans 2: Non-Conventional Current: The amount of electric charge that flow through a cross section of a conductor per unit time is known as electric current.It is also known as non-conventional current.

Question # 5

How is the XOR gate so called?

Ans 1: One of its most commonly used applications is as a basic logic comparator which produce a logic "1" output when its two inputs bits are not equal.Because of the ,the XOR gate has an inequality status being known as an odd functions.

Question # 6

How the power is lost due to eddy current in a transformer and how this loss can be minimized?

Ans 1: The induced currents that are set up in the core of transformer in the direction perpendicular to the flux are known as eddy currents,It results in power dissipation and heating of the coral material.The insulation between lamination sheets should be perfect so as to stop the flow of eddy currents.

Question # 7

Define retantivity.

Ans 1: When the current is reduced to zero,the material still remains strongly magnetized which is known as retantivity.

Question # 8

State uncertainty principle.

Ans 1: The product of uncertainty in the measurement of momentum and uncertainty in the measurement of position of an electron is approximately equal to Planck's constant.
The product of uncertainty in the measurement of energy and uncertainty in the measurement of time of an electron is approximately equal to Planck's constant.

Question # 9

What is AVO-meter?Explain

Ans 1: It is an instrument which can measure current in amperes potential difference in volts and resistance in ohms.It basically consists of sensitive moving coil galvanometer which is converted into multirange ammeter ,voltmeter or ohmmeter accordingly as a circuit.

Question # 10

Write a note on LED.

Ans 1: Light emitting diode are made from the special semiconductor such as gallium arsenide and gallium arsenide phosphide in which the potential barrier between p and n side is such that when electrons combines with a hole during forward biased conduction,a photon of visible light is emitted.
LED are used in 7-segment display,small light sources etc.

Question # 11

Briefly give the function of Filament,Cathode,Grid and plates in C.R.O.

Ans 1: Filament: It heats the cathode.
Cathode: It emits the electrons.
Grid:It controls the number of electrons.
Plates: The two sets of plates are used to deflect the beam of electrons along x axis and y axis.

Question # 12

Define electric intensity and give its unit.

Ans 1: The electrostatic force per unit test charge,at a specific point in the electric field is called electric field intensity.Its unit is NC^-1.

Question # 13

What factor make a Fusion reaction difficult to achieve?

Ans 1: A fusion reaction requires large energy and temperature ,up to million degrees centigrades,So a fusion reaction is difficult to achieve.

Question # 14

What is meant by para and ferromagnetic substance?

Ans 1: The orbits and the spin axes of the electrons in an atom are so oriented that their field spot each other and the atom behaves like a tiny magnet.Substance with such atoms are called paramagnetic substance e.g iron.
There are some solid substance in which the atom cooperate with each other in such a way so as to exhibit a strong magnetic field there are called ferromagnetic substance.

Question # 15

What do we mean when we say that the atom is excited?

Ans 1: When energy from some external source is provide to an atom in its normal state,then its electron will jump from lower energy state to higher energy state.And atom is said to be excited.

Question # 16

What is the effect of medium between the charges upon coulomb's force?

Ans 1: .If an insulating material i.e direction is places between the charges ,it will reduce the electrostatic force as compared to free space by factor called relative permittivity.

Question # 17

Define energy.

Ans 1: The magnetic energy stored in the inductor per unit is referred as energy density.

Question # 18

How can you identify that when plate of capacitor is positively charged?

Ans 1: For the identification of positively charged plate of a capacitor golf leaf electroscope is used,For this purpose the plate of capacitor is brought near the positively charged disc of electroscope.If the divergence of the gold leaves increase then the capacitor will be positively charged and vice versa.

Question # 19

Protons and neutron are formed by what types of quarks?

Ans 1: Protons is formed by two up and one down quarks.Neutron is formed by two down and one up quarks.

Question # 20

What is meant by Ferromagnetic substance?

Ans 1: In ferromagnetic substance the atoms cooperate with each other in such a away so as to exhibit a strong magnetic field.In ferromagnetic substance there exists a small region called domain.

Test Name	Total Questions	PDF File	Launch Test
12th Class Physics Chapter 1 Short Questions Preparation	37	Download PDF	Launch Test
ICS Part 2 Physics Chapter 12 Short Questions Preparation	37	Download PDF	Launch Test
12th Class Physics Chapter 2 Short Questions Preparation	35	Download PDF	Launch Test
ICS Part 2 Physics Chapter 13 Short Questions Preparation	35	Download PDF	Launch Test
12th Class Physics Chapter 3 Short Questions Preparation	45	Download PDF	Launch Test
ICS Part 2 Physics Chapter 14 Short Questions Preparation	45	Download PDF	Launch Test
12th Class Physics Chapter 4 Short Questions Preparation	46	Download PDF	Launch Test
ICS Part 2 Physics Chapter 15 Short Questions Preparation	46	Download PDF	Launch Test
12th Class Physics Chapter 5 Short Questions Preparation	29	Download PDF	Launch Test
ICS Part 2 Physics Chapter 16 Short Questions Preparation	29	Download PDF	Launch Test
12th Class Physics Chapter 6 Short Questions Preparation	45	Download PDF	Launch Test
ICS Part 2 Physics Chapter 17 Short Questions Preparation	45	Download PDF	Launch Test
12th Class Physics Chapter 7 Short Questions Preparation	32	Download PDF	Launch Test
ICS Part 2 Physics Chapter 18 Short Questions Preparation	32	Download PDF	Launch Test
12th Class Physics Chapter 8 Short Questions Preparation	38	Download PDF	Launch Test
ICS Part 2 Physics Chapter 19 Short Questions Preparation	38	Download PDF	Launch Test
ICS Part 2 Physics Chapter 20 Short Questions Preparation	31	Download PDF	Launch Test
12th Class Physics Chapter 10 Short Questions Preparation	52	Download PDF	Launch Test
ICS Part 2 Physics Chapter 21 Short Questions Preparation	52	Download PDF	Launch Test

Latest Educational News Stories

Pakistan's Largest Database of Colleges and Universities

BS Programs

University Past Papers

University Results

Exam Results 2024

Study Abroad Programs and Opportunities for Pakistani Students

Online Short Questions Preparations

Physics ICS Part 2 Physics Full Book Short Questions Preparation