Question

1. What is the relationship between wavelength and the penetrating power of an electromagnetic wave?

A) The penetrating power has no relationship to the wavelength.

B) The penetrating power increases as the wavelength increases.

C) The penetrating power decreases as the wavelength increases.

D) The penetrating power decreases as the wavelength decreases.


2. As ice melts and turns into water, the speed of sound through the material would most likely do what? Justify your answer.

A) The speed would not change because the material is always water.

B) The speed of sound would increase because the density of water is less than that of ice.

C) The speed of sound would increase because energy is added to ice in order to make it melt.

D) The speed of sound would decrease because sound travels faster through solids than liquids.


3.Which of these waves need a medium to travel through?

A) sound

B) x-rays

C) infrared rays

D) visible light

Answer 1

#1

As we know that energy of electromagnetic wave is given by

`E = (hc)/(\lambda)`

so here we know that penetrating power will directly depends on its energy and energy inversely depends on wavelength

So here we can say correct answer will be

C) The penetrating power decreases as the wavelength increases.

#2

Speed of sound is maximum in solids and minimum in gas

so here as ice melts into water the speed of sound must have to decrease

so correct answer will be

D) The speed of sound would decrease because sound travels faster through solids than liquids.

#3

mechanical waves required medium to travel while non mechanical waves do not require any medium to travel

so here correct answer will be

A) sound