SUBJECT : GENERAL PHYSICS

TOPIC : PHYSICAL QUANTITIES AND RELATIONSHIP BETWEEN VARIABLES

TOTAL OF 15 QUESTIONS

1) The voltmeter shown below measures voltage in terms of the unit volt (V). What is its least count? 6 2 V 10 718 YS-670 Ao CLASS 25 teachos tea@ teachoo.com COM teacho LOO.COM O 2.0V 0.20 V 1.0 V O 0.40 V2) What is the standard SI unit of length, mass and time, respectively? * O meter, gram, second O meter, kilogram, second O kilometer, gram, second kilometer, kilogram, second For items 3 and 4, refer to this: Annika, Sarah, and Ciara measured the magnitude of the acceleration due to gravity of a falling object using different experimental procedures. They repeated their experiment thrice. The magnitude of their measured acceleration per trial are shown in the table below. For the location of their experiment, the actual magnitude of the acceleration due to gravity is 9.80 m/s^2. Magnitude of Acceleration (m/s?) Experimenter Trial 1 Trial 2 Trial 3 Annika 9.60 9.61 9.60 Sarah 9.70 9.85 9.65 Ciara 9.80 9.82 9.793) Who measured the most precise set of data during her experiment? * O Ciara Annika O Sarah 4) Who measured the most accurate set of data? * Ciara Annika Sarah 5) Two laboratories use radiocarbon dating to measure the age of a wooden spear handle found in an ancient grave. Lab A uses an instrument with a least count of 10 years. Lab B uses an instrument with a least count of 50 years. Which of the following statements is true? O Lab A used a more precise instrument than Lab B. Lab B used a more precise instrument than Lab A. Lab A used a more accurate instrument than Lab B. Lab B used a more accurate instrument than Lab A.6) Imagine that you are a senior high school physics teacher. Your student states * in a report that the time required for a 700-kg horse to circle a 2.25-km track is 120.41456 seconds. This was measured using a clock with a least count of 0.1 second. Is the reported data possible? Why? Yes. It is measured using an accurate and precise instrument. O Yes. It falls within the average speed for horses of the same size and built. No. It is not possible for a horse to move that fast. O No. It is not possible to record that time with a clock that has a 0.1-second least count. 7) The power rating of a machine is measured in Watts, which is equivalent to Joules per second (J/s). Assume that you do not know what Joules is, you saw that an airconditioner is rated 1000 Joules. You let it run for 1 second. How will you determine the airconditioner's power rating? divide 1000 Joules by 1 second O multiply 1000 Joules by 1 second O divide 1 second by 1000 Joules O multiply 1 second by 1000 Joules8) Which ruler has better precision? * 3 4 5 6 7 8 9 10 11 12 19 14 15 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Ruler A O Ruler B Neither of the two. Rulers are too O The two rulers have the same level O obsolete and cannot give precise of precision. measurement.9) Which can improve precision? * O reducing random errors O using instruments with smaller least count O repeating the experiment with several trials O all of the above 10) Why is there a need to standardize units of measure of physical quantities? * to ensure fairness, such as in buying commodities to ensure safety, such as when constructing a house to ensure proper discovery, such as when conducting an experiment all of the above 11) The smallest possible division in which a measuring instrument can measure * is called its least count O random error O smallest count degree of accuracy12} In 2m 1. some neutrinos (sub-atomic particles} were discovered to travel faster than the speed of light. This challenged physicists around the world because the laws of nature prohibit travelling faster than light. Upon further investigation, it was revealed that a faulty wire connection in one of the instruments caused the error. What type of error is this? 0 random error 0 systematic error 0 both random and systematic errors 13} The observed relationship between two variables is valid if and only if . * 0 both variables increase 0 both variables decrease 0 other variables are held constant 0 other variables follow the observed relationship For items 14 and 15. refer to the equation below. E, El and Ft are variables. k is a constant. _E E_ R2 14) Which pair of variables follow inverse square proportion? * Q and R E and R O Q and E E and k 15) An increase in which variable will result in a decrease in variable E assuming * that the other variables are held constant? O k O OR All of the above