Waec physics practical guide 2022

? *OBSERVATION ON Question 1*

✓ Record L^-1 to the required accuracy to avoid difficulties in plotting graph.
✓ Evaluate and record five values of L^-1 to at least 3 d.p
✓ Show composite table (containing the required variables in the question)

? *OBSERVATION ON Question 3*

✓ Record I^-1 or L^-1 to the required accuracy to avoid difficulties in plotting graph.
✓ Evaluate and record five values of I^-1 or L^-1 to at least 3 d.p
✓ Show composite table (containing the required variables in the question)

?? *PLOTTING GRAPHS*

1. Both axes correctly distinguished.
2. Plot a graph using reasonable scales.
3. Draw line of best fit.
4. Determine the slope and intercept of the graph.
5. Evaluate correctly.

*PRECAUTIONS*

*State any two of the following precautions for QUESTION 1.*

i. I avoided draught.
ii. I avoided parallax error in reading metre rule.
iii. I ensured suspended masses did not touch the table.
iv. I noted zero error on the meter rule.

*State any two of the following precautions for QUESTION 3.*

i. I ensured I open the key when not taken readings.
ii. I avoided parallax error when taking the readings on the ammeter.
iii. I ensured zero error was noted and corrected on the ammeter.
iv. I clean and tight connection of the terminals.
v. I ensured the Jockey not slide/drag on potentiometer wire.

*In Part b, QUESTION 1*

? The expected Questions are:

(i) *State the principle of moment*

The principle of moments states that for a body in equilibrium, the sum of the clockwise moments about a point is equal to the sum of the anticlockwise moments about the same point.

(ii) *Define Center of Gravity*

The centre of gravity of a body is defined as the point through which its resultant
weights acts.

OR
The point where the weight of the body acts or appears to act.

OR
The point through which the line of action of the weight of the body passes irrespective of the position or shape of the body.

(iii) Define Moment of force

(iv) Calculations on moment of force

(v) State the conditions necessary for equilibrium

(vi) Why is center of gravity does not have effect on a body at equilibrium?

*In Part b, QUESTION 3*

? The expected Questions are:

(i) Define emf of a cell

(ii) Define potential difference