Waec Physics 2018 Past Questions and Answers

Question 56:

• WAEC 2018

(a) What is an intrinsic semiconductor?
(b) Distinguish between the p-type and n-type semi-conductors.

Question 57:

• WAEC 2018

A missile is projected so as to attain its maximum range. Calculate the maximum height attained if the initial velocity of projection is 200 ms\(^{-1}\). [g = 10ms\(^{-2}\)]

Question 58:

• WAEC 2018

A black body radiates maximum energy when its surface temperature T and the corresponding wavelength \(\lambda\)max are related by the equation \(\lambda\)max T = constant. Given the values of the constant and surface temperature as 2.9 x 10\(^{-3}\) mK and 57°C respectively; Calculate the frequency of the energy radiated.

Question 59:

• WAEC 2018

a) What does the acronym LASER stand for?
b) What is a laser?

Question 60:

• WAEC 2018

(a) Define uniform acceleration.
(b) Forces act on a car in motion. List the
(i) horizontal forces and their directions;
(ii) vertical forces and their directions

(c) A car starts from rest and accelerate uniformly for 20s to attain a speed of 25 ms\(^{-1}\). It maintains this speed for 30s before decelerating uniformly to rest. The total time for the journey is 60s.
(i) Sketch a velocity-tune graph for the motion.
(ii) Use the graph to determine the (\(\alpha\)) total distance travelled by the car (\(\beta\)) deceleration of the car.

The figure here illustrates force-extension graph for a stretched spiral spring. Determine the work done on the spring.