IGCSE Physics Paper-1: Specimen Questions with Answers 71 - 73 of 149
Question number: 71
Question
A man tunes his radio from 10 to 60. What does the 60 explain?
Choices
| Choice (4) | Response | |
|---|---|---|
a. | its speed | |
b. | its amplitude | |
c. | its wavelength | |
d. | its frequency | |
Answer
b.Explanation
Here man turns his radio from 10 to 60.
Unit of frequency is Hz or 1/s, unit of speed is and unit of wavelength is meter.
Only amplitude is unit less. So man turns amplitude of radio
Question number: 72
Question
Explain graph between potential difference and current, known that potential difference changes with changes in current through the wire.
Choices
| Choice (4) | Response | |
|---|---|---|
a. |  A Graph of Current Versus Potential Difference | |
b. |  Graph of Current Versus Potential Difference Given. | |
c. |  Graph of Current Versus Potential Differences. | |
d. |  Graph of Current Versus Potential Difference | |
Answer
d.Explanation
From Ohm’s Law graph of current vs potential difference is always straight line passing throw origin.
If p. d is zero, current will also zero.
Question number: 73
Question
Find the amount of sample left after 20 hours if the half-life is 5 hours and has 0.48g of the substance.
Choices
| Choice (4) | Response | |
|---|---|---|
a. | 1.92 g | |
b. | 7.68 g | |
c. | 0.03 g | |
d. | 0.12 g | |
Answer
b.Explanation
Here from given data
Formula of half-life is given as,