Which of the following instruments may be used to measure relative humidity?
Hydrometer
Manometer
Hygrometer
Hypsometer
Correct answer is C
A hygrometer is an instrument that is used to measure water vapor in the atmosphere. This is also commonly referred to as relative humidity in the atmosphere.
9.0kjkg\(^{-1}\)
84.0kjkg\(^{-1}\)
134.0kjkg\(^{-1}\)
168.0kjkg\(^{-1}\)
Correct answer is C
Heat involved (H) = 88,000J, Mass(M)= 0.5kg, specific heat capacity of water(C) = 4200JkgºC,
Specific latent heat of fusion(L) = ?, Temperature change(Δθ) = θ2 - θ1 = (10 - 0)° = 10°
H = MCΔθ + ML
or
H = M(CΔθ + L) -->\(\frac{H}{M}\) = CΔθ + L
: L = \(\frac{H}{M}\) - CΔθ = \(\frac{88,000}{0.5}\) - 4200 \(\times\) 10
L = 176,000 - 42000 = 134,000
L = 134,000 or 134kj/kg
46.0 Nm\(^{-2}\)
75.0 Nm\(^{-2}\)
80.0 Nm\(^{-2}\)
85.3 Nm\(^{-2}\)
Correct answer is B
Using \(\frac{P_{1}}{T_{1}} = \frac{P_{2}}{T_{2}}\)
P\(_{1}\) = 80Nm\(^{2}\)
T\(_{1}\) = 47 + 273 = 320k
T\(_{2}\) = 27 + 273 = 300k
P\(_{2}\)?
\(\therefore\) = P\(_{2}\) = \(\frac{P_{1}T_{2}}{T_{1}}\)
= \(\frac{80 \times 300}{320}\) = 75.Nm\(^{2}\)
In which of the following media is the speed of sound the least?
Air
Brass
Water
Wood
Correct answer is A
No explanation has been provided for this answer.
A transverse pulse of frequency 9 Hz traves 4.5m in 0.6 s. Calculate the wavelength of the pulse.
3.33 m
0.30 m
0.83 m
1.20 m
Correct answer is C
Wavelength (\(\alpha\)) = \(\frac{Velocity (V)}{Frequency (f)}\)
Velocity = \(\frac{Distance}{Time}\) = \(\frac{4.5}{0.6}\)
= \(\frac{7.5}{9.0}\)
= 0.83m