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what is velocity selector?
Answer
It is a device consisting of perpendicular electric and magnetic fields that can be used as a velocity filter for charged particles
what is pure substance
A sample of matter with both definite and constant composition with distinct chemical properties is known as pure substance
What mass of NaCl must be dissolved in 65 g of water to lower the freezing point by 7.5 degree Celcius, Kf for water= 1.86 Kkgpermol. Assume Van't Hoff factor for NaCl i = 1.87.
∆T_{f} = i k_{f} m
7.5 = 1.87 × 1.86 × (No. of mole)/(Mass of solvent in kg)
7.5 = 3.4782 × (a/58.5)/(65/1000)
7.5 = .9147 × a
So, a = 8.2 gm
Determine the current in each branch of network
You forgot to attach the diagram .
Conductivity of CH3COOH decreases on dilution. why?
On dilution ,we are increasing the amount of water and volume so, the no. of ions which were present before remains same but per unit volume , the no. of ions decreases.so, the concentration decreases.Hence, conductivity decreases.
How viruses replicate
Viruses reproduce through the replication of genetic material, i.e DNA or RNA.
They are simply a strand of DNA or RNA, inside a protein coat. They infect a host cell and use the host cells machinery to make lots of copies, so many that the cell bursts and infects other cells around it! They can make more viruses very quicklytwo wires A and B of the same material and having same length , have their cross sectional areas in the ratio 1:6. what would be the ratio of heat produced in these wires when same voltage is applied across each?
Let the area be x and 6x
so, Ratio of resistance(R1 : R2) = (ρl/x) : (ρl/6x) = 1 : 1/6 = 6 : 1
H = (V²/R)t
so, ratio of heat produced = (V²/R1)t : (V²/R2)t = R2 : R1 = 1 : 6
consider f: R+ implies [-9, infinity] given by f(x)= 5x^2+6x-9. prove that f is invertible with f^-1(y) = (underroot(54+5y) -3)/ 5
R^{+} → [-9 , ∞)
So, its inverse is [-9 , ∞) → R^{+}
x = 5y² + 6y – 9 (y is inverse function)
5y² + 6y – 9 – x = 0
5y² + 6y + (-9 – x) = 0
y = [- 6 ± √(36 + 20(9 + x)]/10 = [- 6 ± 2√(9 + 45 + 5x)]/10 = [ - 3 ± √54 + 5x ]/5
so, y = [ - 3 + √54 + 5x ]/5
so, f^{-1}(x) = [ - 3 + √54 + 5y ]/5
if tan^-1 (x-3/x-4) + tan^-1(x+3/x+4) = pie/4, then find the value of x
why do amiines react as nucleophilles?
A nucleophile is something which is attracted to, and then attacks, a positive or slightly positive part of another molecule or ion. All amines contain an active lone pair of electrons on the very electronegative nitrogen atom. It is these electrons which are attracted to positive parts of other molecules or ions.
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