JAMB Physics Past Questions & Answers - Page 20

96.

According to kinetic molecular model in gases,

A.

the particles are closely packed together; they occupy minimum space are usually arranged in a regular pattern

B.

the particles vibrate about fixed positions and are held together by the strong intermolecular bonds between them

C.

the molecules are very far apart and occupy all the spaces made available to them

D.

the particles occur in clusters with molecules slightly further apart

Correct answer is C

The model, called the kinetic theory of gases, assumes that the molecules are very small relative to the distance between molecules.

The molecules are in constant, random motion and frequently collide with each other and with the walls of any container.

97.

A magnet relay is a device used for?

A.

reading the magnitude of magnetic flux

B.

controlling another circuit carrying larger current

C.

turning in sports

D.

storing magnetic field

Correct answer is B

Relays are electrically operated switches that open and close the circuits by receiving electrical signals from outside sources.

98.

When the plate area of a capacitor increases?

A.

the voltage can withstand increase

B.

the capacitance decreases

C.

the capacitance is unaffected

D.

the capacitance increases

Correct answer is D

Therefore, as the area of the plates increase, capacitance increases.

99.

A tuning fork having a frequency of 312 Hz emits a wave which has a wavelength of 1.10 m. Calculate the velocity of sound

A.

312.0 ms\(^{-1}\)

B.

110.0 ms\(^{-1}\)

C.

343.2 ms\(^{-1}\)

D.

686.4 ms\(^{-1}\)

Correct answer is C

v = f λ to calculate the wave's velocity.

v = 312 x 1.10

= 343.2m/s

100.

A person standing waist-deep in a swimming pool appears to have short legs because of light?

A.

diffraction

B.

refraction

C.

reflection

D.

interference

Correct answer is B

The refractive index of water is greater than that of air.

So, A person legs appear to be short while standing in the tank due to refraction.