100% VERIFIED 2016/2017 WAEC PHYSICS ESSAY AND OBJ ANSWERS

1-10)CCBBCBDBCD (11-20)DACADCAADB (21-30)BACBBBDDBD (31-40)DDDBDABABA (41-50)BCAADABCDC No2) V/u = sin θ Vy = u sin θ Vy = 20 sin 40 Vy =12.86m/s (No4) Given flux density(B)=0.217 Force(F)=9.6*10^-12N Speed(v)=? F=Bqv 9.6*10^-12= 0.12* 1.6* V V=(9.6*10^-12)/0.192*10^-19 =50*10^-12+9 v=50*10^7 =5*10^8ms^-1 11a) Dielectric strength is the property of an insulating material to retain material to retain electrical properties 11bi) -Infra-red wave -Geiger muller counter -Scintillation counter 11bii) Irradiation of solar energy 11c) Charge(q)=1.0*10^-19C Electric field intensity(E)=1200NC^-1 Weight of the oil drop=? E=F/q 1200=F/1.0*10^-19 F=1200*1.0*10^-19 F=1.2*10^3*10^-19 F=1.2*10^-16N 11d) R=100ohm, L=0.05H, C=0.25uF V=220v, f=50Hz 11di) Impedance(z)=sqroot(R^2+(Xl-Xc)^2) Xl=2*pie*fl Xl=2*(22/7)*50*0.05 Xl=15.71ohm Xl=(1/2*pie*fc) Xc=1/78.55*10^-6 Xc=10^6/78.55 =12730.7ohm Z=sqroot(100^2+(15.71^2-12730.7^2) Z=sqroot(10000+2.63*10^16 Z=sqroot(2.63*10^16) Z=1.62*10^16ohm Are you writing Post-UTME this year? Click Here to Participate on our Past Question CBT Center 11dii) Vrms=IZ I=220/1.62*10^16 =1.36*10^-14 10a) Critical angle is the angle of incidence in the optically densed medium when the angle of refraction is 90degrees 10b) Anti-note are created by region of maximum displacement in a wave (No5) -for exploration of space -it is used for war fare -it is used for launching of satellite (No6) (a)doping is the process of producing an impure semiconductor by adding foreign elements to the pure semiconductor (b)Doping a semiconductor improves the number of charge carriers (No3) -smoke -aerosol -dust particle (No4) Given flux density(B)=0.217 Force(F)=9.6*10^-12N Speed(v)=? F=Bqv 9.6*10^-12= 0.12* 1.6* V V=(9.6*10^-12)/0.192*10^-19 =50*10^-12+9 v=50*10^7 =5*10^8ms^-1 (No2) Velocity(u)=20ms^-1 Angle(tita)=40 degree At maximum height, h V^2=u^2 + 2gh U^2 sin^2 tita+u u= 20^2* (sin 40 degree)^2 u=20^2*(sin 4o degree) u=400* 0.3455 u=138.2ms^-1 (No1) (a) impulse(I)=F*t F=ma= m(v/t)= M((d/t)/(t)) f=M(l/T)/T)= MLT^-2 I=MLT^-2 * T I=MLT^-1 (b) Acceleration(a)=v/t=(d/t)/t a=d/t^2= L/T^2= LT^-2 (c) WOrk(w)=f*d W=MLT^-2 * L W=ML^2T^-2 ——————— (10a) Critical angle is the angle of incidence in the optically densed medium when the angle of refraction is 90degrees (10b) Anti-note are created by region of maximum displacement in a wave (9a) (i) thermal equilibrium is the point at which the temperature of an object remain constant or steady (ii)fundamental interval is the distance between upper and lower fixed point of a thermometre (9b) (i) it can be used to raise heavy load (ii) it is used in printing press (9c) magnet (9di) by using calometry law heat last = heat gain MmCmDθm=CaDθ + Mw Cw Dθ 300 Cm ( 85 - 40 ) = 90 + 500 * 4200 13500Cm = 90 + 29400000 13500CM = 29400090/13500 Cm=2177.78Jg^-K^-1 9dii) § (i) by convection (ii) by conduction (9diii) § (i) power generation (ii) chemical processing

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