Physics Objective and Theory Questions And Answers.

*PHYSICS OBJ*

1-10 CAABACBADB

11-20 ACCCDABDCC

21-30 DBADCABCAB

31-40 CCBBCCBABD

41-50 BDCDBABBDC

THEORY ANSWERS

(1a)
Strain can be defined as the ratio of extension per unit length Strain=extension/length

(1b)
Strain=extension/length
Let original length=L
Final length=2L
Extension=2L-L=L
Strain=L/L=1

(2)
(i) Silicon Dioxide
(ii) Silica Powder
(iii) Germanium Tetrachloride

(3)
(i) Ferromagnetic material
(ii) Diamgentic material
(iii) Pamangentic material

(4a) An intrinsic semiconductor is an undoped semiconductor that is a pure semiconductor without any significant dopant species present.

(4b) The P Type semiconductor is a type of semiconductor that carries a positive charge, while the N type semiconductor carries a negative charge.

(5)
Range = u²Sin2tita/g
At maximum range
Sin2tita = 1
2tita =sin^-1(1)
2tita = 90dgrees
Tita = 90/2 = 45degree
Maximum height reached = u²sin²tita/2g
=u²(sin45)²/2g
=200²(sin45)²/2(10)
=40000(1/√2)2/20
=40000(1/2)/20
=20000/20
=1000metres.

(6)
Given constant = 2.9×10^-3mk
Temperature = 57degreeC = (57 273)k = 330k
Using landamaxT = constant
landamaxT330 = 2.9×10^-3
landamax = 2.9×10^-3/330
landamax = 8.788×10^-6m
The speed of electromagneticwave, v = 3×10^8m/s
Using V = f landa
f = v/landa
=3×10^8/8.788×10^-6
=3.4×10^13Hz

(7a)
LASER stands for Light Amplification by Stimulated Emission of Radiation.

(7b)
Laser is a device that generates an intense beam of coherent monochromatic light or other electromagneticradiation by stimulated emission of photons from excited atoms or molecules
=====================

(9ai)
(i) Nature of the Substance
(ii) Medium of transmission

(9aii)
(i)State or phase of the substance (i.e Solid, Liquid or gas).
(ii)Temperatureof the medium

(9b)
(i) Temperature
(ii) Specific hear capacity of the body

(9c) The statement means that the amount of hear energy required to change 1kg of liquid mercury to gaseous mercury without change in temperature is 2.72*10^5Kg^-1
=====================

(10bi) Critical angle is the highest angle of incidence in a denser medium when angle of refraction in the less dense mediumis 90 degrees

(10bii) Critical angle=90-44=46degrees The refractive index of the glass is obtained as follows The refractive index(n)=sini/sinr=sin46/sin90=0.7193/1 =0.7193 (10ci) fo=200Hz f1=3v/4l =>closed pipe f1=v/l=>open pipe but 3fo=f1=>closed pipe 3*200=f1=>f1=600Hz Also f1=2fo=>open pipe 2fo=600 fo=600/2=300Hz (10cii) v=330m/s L=? fo=200Hz fo=v/4l =>200=330/4l 800l=330 l=330/800 l=0.4124m

(10ciii) fo=v/2l fo=300Hz v=330m/s 300=330/2l l=330/600 l=0.55m

(12a) This is defined as the amount of energy that must be supplied to a nucleus to completely separate it’s nuclear particles (nucleons)

(12b)
(i) They have short wavelength and high frequency.
(ii) They are highly penetrating.
(iii) They travel in straight lines.
(iv) They don’t require material medium for their propagation.

(12c)
-It is used in production of electricity.
-It is used to study and detect charges in genetic engineering.
-It is used in agriculture.
-It is used in treatment of cancer.

=======GOODLUCK======