1.1 - Units, Significant Figures, and Measurement

Which of the following units is not a unit of power?

• A. $\hspace{1em}$ W

• B. $\hspace{1em}$ J

• C. $\hspace{1em}$ N m s$^{-1}$

• D. $\hspace{1em}$ J s$^{-1}$

Which of the following is an estimate of the order of magnitude of the radius of the Earth?

• A. $\hspace{1em}10^{7} \,m$

• B. $\hspace{1em}10^{11}\, m$

• C. $\hspace{1em}10^{15}\, m$

• D. $\hspace{1em}10^{22} \,m$

Which of the following is not a fundamental SI unit?

• A. $\hspace{1em}$ampere

• B.$\hspace{1em}$ kelvin

• C. $\hspace{1em}$newton

• D.$\hspace{1em}$ mole

A student models the relationship between velocity v of a moving charge in a magnetic field, and the force $F$ acting on it as $F = kv$, with $k$ being a constant

What are the units for $k$ expressed in fundamental SI units?

• A. $\hspace{1em}m \,s$

• B. $\hspace{1em}kg \,s^{-1}$

• C. $\hspace{1em}kg \,s^{-2}$

• D. $\hspace{1em}m \,s^{-2}$

How many significant figures are there in 0.000017000?

• A.$\hspace{1em}$ 2

• B.$\hspace{1em}$ 5

• C.$\hspace{1em}$ 6

• D. $\hspace{1em}$9

Express 0.04758 to 3 significant figures.

• A. $\hspace{1em}$0.04758

• B. $\hspace{1em}$0.0476

• C. $\hspace{1em}$0.048

• D. $\hspace{1em}$0.05

Which of the following gives the unit of electric potential in fundamental SI units?

• A. $\hspace{1em}$ $kg\,m^2\,s^{-3}\,C^{-1}$

• B. $\hspace{1em}$ $kg\,m^2\,s^{-1}\,A$

• C. $\hspace{1em}$ $kg\,m^2\,s^{-2}\,C^{-1}$

• D. $\hspace{1em}$ $kg\,m^2\,s^{-3}\,A^{-1}$

Which of the following gives the unit for work in fundamental SI units?

• A.$\hspace{1em} m^2\,s^2$

• B.$\hspace{1em} kg\,m\,s^{-1}$

• C.$\hspace{1em} kg\,m^2\,s^{-1}$

• D.$\hspace{1em} kg\,m^2\,s^{-2}$

Which of the following is $\textbf{not}$ a unit for magnetic flux density?

• A. $\hspace{1em}$ $T$

• B. $\hspace{1em}$ $Wb\,m^2$

• C. $\hspace{1em}$ $kg\,s^{-2}\,A^{-1}$

• D. $\hspace{1em}$ $N\,A^{-1}\,m^{-1}$

Which of the following is equivalent to the unit of electric potential difference?

• A. $\hspace{1em} N \,m \,C^{-1}$

• B. $\hspace{1em} N \,m^{-1} \,C^{-1}$

• C. $\hspace{1em} J \,C$

• D. $\hspace{1em} J\, m^{-1} \,C^{-1}$

What is the unit of capacitance expressed in fundamental SI units?

• A. $\hspace{1em}kg^{-1}\,m^{-2}\,A^2\,s^4$

• B. $\hspace{1em}kg\,m^2\,A^{-2\,}s^{-4}$

• C. $\hspace{1em}kg^{-1}\,m^{-2}\,C^2\,s^2$

• D. $\hspace{1em}kg\,m^2\,C^{-2}\,s^{-2}$

A body moves a distance of 1.5 $km$ in 10 $ks$.

Which of the following gives the correct magnitudes of both of distance and time?

The diagram shows a cube of side length $0.010\,m$ and a metal sphere of radius $0.5\,cm$. The image below is not to scale.

$\footnotesize{\textrm{[Source: OpenClipart-Vectors from Pixabay https://pixabay.com/vectors/ball-balls-glass-glow-glowing-1293319/ ]}}$

If there is a set of these spheres that could be melted down, what is the estimated number of spheres required to construct the cube from the material?

• A.$\hspace{1em}$ 20

• B. $\hspace{1em}$10

• C.$\hspace{1em}$ 4

• D.$\hspace{1em}$ 2