Why do the waves have different speeds in different layers of Earth's surface?
1 answer:
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Answer:
The number of turns in the secondary coil is 48.
(B) is correct option.
Explanation:
Given that,
Number of turns on primary coil= 1000
Primary voltage = 2500 V
Secondary voltage = 120 v
We need to calculate the turns in the secondary coil
Using relation between voltage and number of turns in primary and secondary coil
Put the value into the formula
Hence, The number of turns in the secondary coil is 48.
Answer:
78g
Explanation:
Given parameters:
Mass of oxygen gas = 16g
Mass of potassium oxide = 94g
Unknown:
Mass of reacting potassium = ?
Solution:
To solve this problem, we need to obtain a balanced reaction equation. Then determine the number of moles of the reactant and use it to find that of the other one.
Balanced equation:
4K + O₂ → 2K₂O
Number of moles of reacting oxygen;
Number of moles =
molar mass of O₂ = 2 x 16 = 32g/mole
Number of moles = = 0.5mole
From the reaction equation;
4 mole of K reacted with 1 mole of O₂;
x mole of K will react with 0.5 mole of O₂
Therefore, 4 x 0.5 = 2 moles of potassium.
Mass of potassium = number of moles x molar mass
Molar mass of potassium = 39g
Mass of potassium = 2 x 39 = 78g