physics exam unit one

estimate the absolute error in measuring the length of a pencil if the result is 12.3 cm and the actual value is 12.10 cm

• -0.2 cm

• 0.02 cm

• 0.2 cm

• 2.2 cm

estimate the relative error in measuring the length of a pencil if the result is 12.3 cm and the actual value is 12.10 cm

• 1.65%

• 0.01%

• 0.1%

• 1%

• 0.165

• 0.174

• 1.654

• 0.0147

the metric unit of intensity of current is :

• ampere

• kelvin

• candela

• kg

 $E=m\ .\ g\ .\ d\$  the formula to calculate energy thus the dimensions of  energy is

( m = mass   g = acceleration   d = displacment

•  $M\ L^2\ T^{-2}$  

•  $M^{0\ \ }L^2\ T^2$  

•  $M\ L^2\ T^2$  

•  $M^2\ L^2\ T^{-2}$  

• 0.2 kg

• 0.02 kg/m3

• 0.2

• 0.02

the difference between the measured value and the actual error

• absolute error

• relative error

• the error

 $M\ \ \ L\ \ T^{-2}$  the dimensions of force thus the unit of it is :

•  $Kg\ m\ s^{-1}$  

•  $Kg\ m^{-1}\ s^{-2}$  

•  $m\ s^{-2}$  

•  $kg\ m\ s^{-2}$  

the most accurate standard measure of time is

• standard second

• atomic clock

• solar day

• cesium

• 0.8 m

• 0.08

• 0.08 m

• 0.8