physics 1 exam (B)

which product -pair of meteric prefix has the greatest magnitude ?

• femto x mega

• Nano x kilo

• micro x Giga

• milli x tera

Platinum – iridium alloy not glass is used to make standard units because …

• It is rigid

• Chemically inactive

• Does not affect by surrounding temperature

if the radius of a virus is 5.1 nm, then the diamter of the virus equals..............

• 10.2 x  $10^{-3}\ \mu m$  
  

• 1.02 x  $10^{-7}mm$  
  

• 10.2 x  $10^{-8}m$  
  

• all the pervious
  

if the dimensional formula of a physical quantity is M⁰ L T^-2 , the measuring unit of this quantity is …..

• kg m/s²

• kg s^-1

• m/s

• m s^-2

The measuring unit of work in British system is ………………

• pound foot^-1/s²

• pound foot²s²

• pound foot²/s²

• pound foot^-2s^-2

if the dimensional formula of a physical quantity is MLT^-1, then its measuring unit is……………

• kg.m.s

• kg/s

• kg.m.s^-1

• kg.m^-1.s

the pressure =  $\frac{\text{force}}{\text{area}}$  so the measuring unit of pressure in French  system is ……….

• g /cm s 

• g /cm  $s^2$  

• g cm/ $s^2$  

• g /  $cm^2\ s^2$  

 a metallic ball of radius r is dropped into a tank of water, if its velocity in water was v and affected by a resistance force given by the relation F= Krv where K is constant, then the measuring unit of K is….

• Kg. $m^2.s^{-1}$  
  

• Kg. $m^{-2}.s^{-2}$  
  

• Kg. $m^{-1}.s^{-1}$  
  

• Kg.m. $s^{-2}$  
  

The power calculated from the following rule    (power =   $\frac{\text{w}}{\text{t}}$   )    w is work      ,      t is time        , so the unit of power in SI      is ….

• Joule/ s 

• kg  $m^2s^{-2}$  

•  kg m  $s^{-3}$    

• kg $m^2s^{-3}$  

area of class is 24m², find its area in (cm²) is ……………..

• 24 x 10^-4

• 24 x 10⁴

• 24 x10²

• 24 x 10^-2