General Science - Online Test
column A
a) Stapes
b) External auditory canal
c) Malleus
d) Incus
column B
i) anvil shaped
ii) hammer shaped
iii)S- shaped
iv) stir-up shaped
A brass boiler has a base area of 0.15 m2 and thickness 1.0 cm. It boils water at the rate of 6.0 kg/min when placed on a gas stove. Estimate the temperature of the part of the flame in contact with the boiler. Thermal conductivity of brass = 109 J ; Heat of vaporization of water = 2256
Base area of the boiler, A = 0.15 m2
Thickness of the boiler, l = 1.0 cm = 0.01 m
Boiling rate of water, R = 6.0 kg/min
Mass, m = 6 kg
Time, t = 1 min = 60 s
Thermal conductivity of brass, K = 109 J s –1 m–1 K–1
Heat of vaporisation, L = 2256 × 103 J kg–1
The amount of heat flowing into water through the brass base of the boiler is
..........(1)
where,
T1 = Temperature of the flame in contact with the boiler
T2 = Boiling point of water = 100°C
Heat required for boiling the water
Q = mL ....… (ii)
Equating equations (i) and (ii), we get:
∴ mL = KA(T1 - T2) t / l
T1 - T2 = mLl / KAt
= 6 × 2256 × 103 × 0.01 / (109 × 0.15 × 60)
= 137.98 o C
Therefore, the temperature of the part of the flame in contact with the boiler is 237.98°C.
X series: Arithmetic average = 65
Standard deviation = 23.33
Y series: Arithmetic average = 66
Standard deviation = 14.9
Summation of products of corresponding deviation of X and Y series = + 2704
Calculate product moment correlation of x and y series.
