Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts
WAEC offline past questions - with all answers and explanations in one app - Download for free

Physics 2021 WAEC Past Questions

Clear Selections
Change Subject Post a Question Check Syllabus Study My Bookmarks Past Questions Videos Watch Video Lessons Download App

Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts
Download WAEC May/June App - Get all past questions and answers, 100% offline - 43208
WAEC Past Questions, Objective & Theory, Study 100% offline, Download app now - 24709
56

State three observable phenomena where a particle behaves like waves. State the scientific principle underlying the operation of fibre optics.

(b) Explain each of the following terms as used in fibre optics: (i) core; (ii) cladding

View Answer & Discuss (5) WAEC 2021
57

(a)(i) State Hooke's law. (ii) A spring has a length of 0.20 m when a mass of 0.30 kg hangs on it, and a length of 0.75 nm when a mass of 1.95 kg hangs on it. Calculate the: (i) force constant of the spring; (ii) length of the spring when it is unloaded. [g = 10m/s\(^2\)]

(b)(i) What is diffusion? (ii) State two factors that affect the rate of diffusion of a substance. (iii) State the exact relationship between the rate of diffusion of a gas and its density.
(c) A satellite of mass, m orbits the earth of mass. M with a velocity, v at a distance R from the centre of the earth. Derive the relationship between the period T, of orbit and R.

 

 

View Answer & Discuss (3) WAEC 2021
58

c(ii)
(a)(i) Define dew point. (ii) Explain why dew forms more quickly on the metal parts than on the rubber parts of a bicycle placed in the open overnight.

(b)(i) Explain the statement. the specific heat capacity of copper is 400 J/kg/K. (ii) Two metals, P and Q are supplied with the same quantity of heat.

If the ratio of the specific heat capacity of P to Q is 3: 1 and their masses are in the ratio I:2 respectively.

calculate the ratio of the temperature rise of P to Q.

(c)(i) Define coefficient of thermal conductivity of a material.

The diagram above c(ii) illustrates a composite bar of iron and copper. The bar is insulated along its sides and it has a diameter of 10 mm. The length and thermal conductivity of the iron are 0.15 m and 40 W/m/K, respectively and those of copper are 0.05 m and 360 W/m/K, respectively. If the free ends of the iron and copper are kept at 100°C and 0°C respectively. calculate the (i) temperature at the interface between the bars; (ii) rate of heat flow along the bar.

View Answer & Discuss (3) WAEC 2021
WAEC Past Questions, Objective & Theory, Study 100% offline, Download app now - 24709
WAEC offline past questions - with all answers and explanations in one app - Download for free
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts
59

(a)(i) Define each of the following terms as it relates to converging lenses (i) focal length; (ii) optical Centre.

(iii) Draw a ray diagram to illustrate how a converging lens is used to produce a virtual image of an object.

(b)(i) Name the primary colors of light. (ii) Match each primary color to its corresponding complementary color.

(c) A ray passes symmetrically through a glass prism of angle 60° and refractive index of 1.5. Calculate the angle of: (i) incidence; (ii) minimum deviation.

View Answer & Discuss WAEC 2021
60

(a)(i) What is meant by the root-mean-square value of an alternating current? (ii) Define impedance of an alternating current circuit.

(b) An electrical device rated 120 V, 60 W is opened on a 240 V, 50Hz mains supply. The circuit has a capacitor connected in series with ihe electrical device and the supply. Calculate the capacitance of the capacitor. [π=3.142].

(c)(i) Define the capacitance of a capacitor.

(ii)

Open photo

The circuit diagram above illustrates two capacitors of capacitance C\(_1\) and C\(_2\) connected in series across a 2V source.

(i)Obtain an expression for the total capacitance in terms of C\(_2\). 2 mm 5 n (ii) Calculate the potential difference across each capacitor.

 

View Answer & Discuss (1) WAEC 2021
Start a Free Practice Test
 
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts
WAEC Past Questions, Objective & Theory, Study 100% offline, Download app now - 24709
Download WAEC May/June App - Get all past questions and answers, 100% offline - 43208
WAEC offline past questions - with all answers and explanations in one app - Download for free