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41. What happens if a man from antimatter world shake with a man from matter world?
When a particle combines with its antiparticle, they annihilate giving rise to a release of energy in the form of photons. If  a man from antimatter world shakes hand with a man from matter world, they annihilate giving large amount of energy in the form of photons as the body of the man from the matter world is made up of particles and that of the man from the antimatter world is made up of antiparticles.
 
 
 
42. X-ray production is the inverse process to that of the photoelectric effect. Is it true?

When light of suitable wavelength is incident on some metal's surface then there is ejection of electrons from that surface of metals. This process is called photoelectric effect. Here, photoelectrons (particles) are liberated from surface of metals by incident light (waves). But X-rays (waves) are produced by bombarding matter with electrons (particles). So, the above statement "X-ray production is the inverse process to that of the photoelectric effect" is absolutely true.

 

43. Why is light not deflected by electric as well as magnetic field?

A ray or particle having some charge is deflected by electric as well as magnetic field. As the light is an electromagnetic but chargeless particle. Hence, light is not deflected by electric as well as magnetic field. 

 

 
44. Why does the resistance of semiconductor decreases with rise in temperature?
When the temperature is raised above the absolute zero, some of covalent bonds breaks due to the thermal energy supplied. Breaking of bonds result to free electrons which are engaged in the formation of covalent bond. So, only a few free electrons exist in semiconductor. These free electrons can constitute a tiny electric current if p.d. is applied across the semiconductor. Hence, semiconductor has negative temperature coefficient of resistance i.e. the resistance of semiconductor decreases with rise in temperature.
 
 
45. What are the regions found in the transistor?

There are three regions found in the transistor. They are emitter, base & collector.

Emitter E: The main function of emitter is to supply majority charge carrier into base so, it is heavily doped in order to emit a number of majority charge carriers.

Base B: Base controls the flow of charges from emitter to collector so, it is very thin & lightly doped.

Collector C: Collector collects the majority charge carriers coming from emitter through base so, it is moderately doped. 

 

46. Write short notes on the biasing of transistor.

Biasing of transistor: For the proper functioning of the transistor different junction of transistor should be properly biased. A transistor is said to be properly biased if base-emitter junction is forward biased & base-collector junction is reverse biased. 

 

47. What is the main function of filter circuit?

The main function of perfect rectifier is to convert an A.C. signal completely to D.C. signal. But no any rectifier is as perfect to convert an A.C. signal completely to D.C. signal. In order to fulfill the objective of rectifier, filter is used in the circuit for proper rectification. The main function of filter circuit is to minimize A.C. signal in the rectifier. Capacitors, inductors, resistors etc are used for the filtering purpose

 

48. What is the use of grid in triode valve?

A triode valve is a vacuum tube consisting of three electrodes: plate (anode), grid & cathode. The grid lies in between the plate & the cathode. The grid controls the flow of electrons from cathode to anode. When the grid is made positive potential then it helps anode to attract electrons in high rate resulting in the increment of flow of current but when grid is made negative potential then grid repels the incoming electrons from cathode & cause the decrease in current in the circuit. This is the use of grid in triode valve.

 

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