Threshhold frequency is defined as the minimum light frequency necessary to start photo-electric emission from the surface. This frequency is just effecient enough to emit electrons without any additional force or energy. this minimum frequency creates the necessary result that is sought by the person. The photo electric emission for certain metals can occir with threshhold frequency. The importance of this threshhold frequency lies in the fact that this has been used to create numerous instruments like amplifiers for use of people.
Answer:
Al2O3 + 3Mg ===》 3MgO + 2Al
Explanation:
Reaction of aluminium oxide with magnesium metal would form magnesium oxide and aluminium metal.
Balancing the stoichiometric equation, the number of atoms at the reactant must be equal to the number of atoms at the product so that law of conservation of matter must hold.
Al203 + 3Mg ====》 3MgO + 2Al
2 aluminium at reactant = 2 aluminium at product
3 oxygen at reactant = 3 oxygen at product
3 magnesium at reactant = 3 magnesium at product.
I believe they are:
Pin Insulators
Suspension Insulators
Strain Insulators
If thats not enough theres also insulators commonly used of lower voltage which are:
Stay
Shackle
Answer:
Explanation:
b) Gravity reduces the initial upward velocity to zero in a time of
t = v/g = 40/10 = 4 s
a) h = v₀t + ½gt² = 40(4) + ½(-10)4² = 80 m
or
v² = u² + 2as
h = (0² - 40²) / 2(-10) = 80 m
Thew energy stored in a capacitor of capacitance 
and voltage between the plates 
is
.
Substituting numerical value
