JAMB Physics Past Questions & Answers

1,141.

The lower and upper fixed points marked on a mecury-in-glass thermometer are 210mm apart. The end of the mercury column in the tube is 49mm above the lower fixed point in a room. What is the temperature of the room in degrees Celsius?

55.3^oC

23.3^oC

49.0^oC

16.1^oC

76.7^oC

View answer & explanation

Correct answer is B

210mm .... 100^oC

49mm .... \(\theta\)

0mm .... 0^oC

\(\frac{49 - 0}{210 - 0}\) = \(\frac{\theta - 0}{100 - 0}\)

\(\frac{49}{210}\) = \(\frac{\theta}{100}\)

\(\theta\) = 23.3^oC

1,142.

Dewpoint is the temperature at which, water vapour in the atmosphere

turns into steam

solidifies into ice pellets

first condenses into liquid form

is just sufficient to cause cooling

has a relative humidity of fifty percent

View answer & explanation

Correct answer is D

No explanation has been provided for this answer.

1,143.

Of two identical tuning forks with natural frequency 256Hz, one is loaded so that 4 beats per second are heard when they are sounded together. What is the frequency of the loaded tuning fork?

260Hz

252Hz

248Hz

264Hz

258Hz

View answer & explanation

Correct answer is B

- When a tuning fork is loaded with wax, the frequency of the tuning fork decreases, I.e when the prongs are loaded, their inertia increases, resulting in decrease of vibrational frequency.

Beat = F2 - F1

4 = 256 - F1

F1 = 252Hz

1,144.

Which of the following statements is (are) NOT correct?

i. pressure changes do not affect the speed of sound in air
ii. the velocity of sound increases with temperature
iii. the quality of the note depends only on its frequency

i only

ii only

iii only

i and iii

ii and iii

View answer & explanation

Correct answer is D

No explanation has been provided for this answer.

1,145.

When vibration occurs in air column, the distance between a node and an antinode is equal to

one-quarter of the wavelength

one-hall of the wavelength