IGCSE Physics Paper-1: Specimen Questions with Answers 68 - 70 of 149
Question 68
Question
MCQ▾What can be explained about motion if small steel ball is dropped from a height?
Choices
| Choice (4) | |
|---|---|
a. | It falls with constant speed. |
b. | It falls with decreasing acceleration. |
c. | It falls with constant acceleration. |
d. | It falls with decreasing speed. |
Answer
c.Explanation
Here steel ball is dropped from height and we ignore air resistance. Therefore there is no any opposite force for motion. So, steel ball dropped with constant gravitational acceleration.
Question 69
Question
MCQ▾Simple mercury barometer and reading is h cm of mercury. Find pressure at S.
Choices
| Choice (4) | |
|---|---|
a. | atmospheric pressure |
b. | h cm of mercury |
c. | atmospheric pressure + h cm of mercury |
d. | approximately zero |
Answer
d.Explanation
here we show barometer is used to measure pressure.
In above figure reading of barometer is h cm. In this barometer is closed so atmospheric pressure is not acting. At point S there is only vacuum present so pressure at S is approximately zero.
Question 70
Question
MCQ▾Aim: Fix a steel washer on to a steel rod. What to do if rod is just too big to fit into the hole of the washer?
Choices
| Choice (4) | |
|---|---|
a. | cool the washer and rod to the same temperature and push them together |
b. | heat the rod and then place it in the hole |
c. | cool the washer and put it over the rod |
d. | heat the washer and place it over the rod |
Answer
d.Explanation
Engineer wants to fix a steel washer on to a steel rod. In above case steel washer is smaller than road
Now, if we apply heat to washer then tightly bounded molecules inside the steel washer are become loose and they expand. Due to it rod is easily fit inside steel washer.