Via: Naija Jokes And Love Text SMS 100% SURE NECO 2014 PHYSICS THEORY & OBJECTIVES QUESTIONS & ANSWERS NOW AVAILABLE HERE Verified and confirmed physics neco obj. 1-50 1-10 DAEDEBACCE 11-20 EADDEADCCB 21-30 DADEBBEAEC 31-40 DBBBBCBBDC 41-50 EBECDBCADD 51-60 BABCBDAADC Physic Theory answer (1a) Force, unit is Newton(N) (1b) Acceleration, Unit is m/s^2 (1c) Velocity, Unit is m/s (2a) It means that the substance contains 10 units of elementary particles and matter (2b) weight of objects varies because of - The spring used in spring balance -The acceleration due to gravity (3a)- Kinetic enegy, A moving car is an example - Potential energy, bird at the top of a tree is an example (3b)Kinetic energy is the energy due to motion while potential energy is the energy by virtue of object (4) MsCs(tita1 - tita3)= MwCw (tita1 -tita3) 320.8*Cs*(100-4 5)= 200*4.2* (45-35. 5) 17600Cs=840* 9.5 Cs= 840*9.5/17600 =7980/17600 Cs= 0.45Jg^-1K^-1 (6) Given t1=6s, t2=4s , V=2d1/t1, 330= 2*d1/6 d1= 1980/2=990m V=2d2/t2, 330=2*d2/4 d2= 1320/2= 660m Distance between the differences : = d1- d2 = 990-660=330m (7a) Electrophorns (7b) It consist of a metal sphere and plates through which any charge objects brought closer to it releases the charge which is stored in the metal sphere (8a) Transformer is called slep-up when the number of turns in secondary is greater than the number of turns in primary (Ns> Np) (8b) Given Ep=2200v, Ip= 40A Ns/Np= 1/12, Es=? Es/Ep=Ns/Np=Ip/ Is 1/12=Es/2200 Es=2200/12 Es=183.3V Secondary voltage=183.3V (9a) - Electromagnetic spectrum - x-ray oscilloscope (b) - they are used in radiological laboratories to study defects in bones - they are used in solar system (10a) - No= initial number of atoms - alpha= decay constant= per time(per second/day) (10b) Given t1/2=20hrs, t=80hrs Using, N/No= (1/2 )^T/t1/2 N/N0=(1/2)^80/ 20 N/No=(1/2)^4 N/No=1/16 SECTION B (11b) Weighing balance (11ci) Static friction is the friction which occurs between two surfaces in contact when there is no relative motion between them. Dynamic friction is the friction which occurs between two surfaces in constant when there is a relative motion between them (11cii) - streamlining of body shape - use of lubricants like grease (11ciii) W=mg Fr=NN, Fr=Nmg N=5.4*10=$5N Recall, u=0,v=4m/s, S=3.6m V^2=u^2 2as 4^2=0^2 2*3.6*s 16= 7.2a a=16/ 7.2 acceleration(a)= 2.22m/s F= ma= 5.4* 2.22 F= 11.988N= 12N from Fr = NN 12=N*54 N=12/54=0.22 (12ai) -Radiation - Convection (12aii) When a metal is heated, the temperature is raised. this increase in temperature of the molecules of the metal causes the metal to vibrate. the Vibratory motion of the molecules causes the election in the metal to move about , there by conducting electricity (12c) Given m=90kg (i)when the elevator starts to ascend, T= m(g a) T=90(10 4) T=90 * 14 T= 1260N (12cii) When it moves with a uniform speed of 15ms^-1, reading on spring balance(T) is T= 0N (iii) When the elevator descends rates at the rate of 3ms^-2 T=m(g-a) T= 90(10-3) T= 90 * 7 T= 630N (13ai) The laws of refraction states that - The incident ray, the normal and the refracted ray all lie in the same plane -The ratio of the sine angle of incidence to the sine of angle of re fraction is a constant for a guven pair of media (13b) Given Near point(V)= 35.0cm Least distance of distinct vision(D)=25cm Using 1/u 1/v=1/f 1/25 1/35=1/fs (15ai) radioisotopes are elements with atomic number of 82 and greater and undergoes radiativitiy by emission of certain radiation (15aii) -treatment of cancer -sterilization of medical equipments (15bi) The energy conversions that take place in the x-ray tube is from radiant energy to kinetic energy of the moving elections. (15bii) -by increasing the intensity of light -by exposure to higher frequency (15biii) Two similarities: -xrays and gamma rays are electromagnetic radiation in nature -x-rays and gamma rays have high penetrating power . Two differences- -xrays are faster in speed than gamma-rays xrays are more energetic than gamma-rays (15c) E2=-2.42 10^-19J E0=-21.8*10^-19 J E=E2-E0 E=-2.42*10^-19- (-21.8^10^-19) E=(-2.42 21.8)*10^-19 E=19.38*10^-19 E=1.938*10^-18j (15Ci) E=HF 1.98*10^-19=6.6 *10^-34*F FREQUENCY(F)= 19.38*10^-19 F=2.94*10^15 (15CII) C=F*LAMDA 3*10^8=2.94*10^ 15*lamda wavelenght=3*10 ^8/ (2.94*10^5) =1.02*10^-7 lamda=1.02*10^- 7m
Posted on: Thu, 19 Jun 2014 08:52:25 +0000