Which of the following waves can propagate through a vacuum?
High velocity sound waves
Ultrasonic waves
Acoustic waves
Infra-red waves
Correct answer is D
No explanation has been provided for this answer.
Determine the distance between the consecutive antinodes XX if the wavelength is 60cm
15cm
30cm
60cm
120cm
Correct answer is B
Distance XX = \(\frac{1}{2}\)\(\lambda\)
= \(\frac{1}{2}\) x \(\frac{60}{1}\)
= 30cm
The relationship between L and the wavelength I of the stationary wave is
2L = \(\lambda\)
L = \(\lambda\)
L = \(\frac {\lambda}{3}\)
4L = 3 \(\lambda\)
Correct answer is D
L = - \(\lambda\) \(\Rightarrow\)4L = 3 \(\lambda\)
200g of water at 90°C is mixed with 100g of water at 30°C. What is the final temperature?
50oC
60oC
70oC
80oC
Correct answer is C
Heat lost = heat gained
200 x c x (90 - \(\theta\))= 100\(\times\) c \(\times\) (\(\theta - 30\))
Dividing through by 100c, we have
2(\(90 - \theta\)) = (\(\theta - 30\))
simplifying, we have
\(\theta\) = 70°
When the volume of a given mass of gas is halved and its temperature doubled, the pressure
remains constant
increases by a factor of 4
increases by a factor of 3
decreases by a factor of 4
Correct answer is B
\(\frac{P_1V_1}{T_1}\) = \(\frac{P_2V_2}{T_2}\)
V1 = 2V2 and T2 = 2T1
\(\frac{P_1\times 2V_2}{T_1}\) = \(\frac{P_2\times V_2}{2T_1}\)
P2 = 4P1