Tag: physics

Quizzes (598) Questions (13441)

Questions Related to physics

Multiple choice physics spectra the electromagnetic spectrum electromagnetic spectrum electromagnetic waves

Electromagnetic waves of wavelength ranging from $100\mathring{A}$ to $\mathring{A}$ comes under 

  1. X-rays

  2. UV regions

  3. Visible region

  4. Infrared region
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
X-rays: $10 nm-10 pm\  i.e.\ 10^{-8}m-10^{-11}m$
Given frequency range: $100 \mathring A-  1 \mathring A\ i.e.\ 10^{-8}m-10^{-10}m$
Hence, given wavelength range falls under X-rays
Multiple choice physics spectra the electromagnetic spectrum electromagnetic spectrum electromagnetic waves

Fill the most suitable option. Mosquitoes and some snakes find their food using vision in the ___ range.

  1. infrared

  2. ultraviolet

  3. radio

  4. microwave

  5. visible light
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Infrared light has longer wavelengths and lower energy than visible light and cannot be seen with the human eye. Mosquitoes, vampire bats, bed bugs, and some snake and beetle species, however, can use portions of the infrared spectrum for vision. Sometimes humans can “see" infrared energy in the form of heat.

Multiple choice physics spectra the electromagnetic spectrum electromagnetic spectrum electromagnetic waves

According to the electromagnetic spectrum, radio waves have the ___frequency and the  _______ wavelength.

  1. lowest; largest

  2. lowest; smallest

  3. highest; smallest

  4. highest; largest

  5. medium; medium
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Radio waves are the least energetic waves among other waves. They have the lowest frequency and thus the largest wavelength. Due to this large wavelength character, the radio waves are used in data transmission purposes, since they are hard to interact with particles in the atmosphere.

Multiple choice physics spectra the electromagnetic spectrum electromagnetic spectrum electromagnetic waves

According to the electromagnetic spectrum, As the frequencies of the pure spectral colours increase, the wavelengths of the colours:

  1. decrease

  2. increase

  3. remain the same

  4. decrease by a factor of 2

  5. increase by a factor of 2
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Speed of all the electromagnetic waves is constant and is equal to speed of light  i.e  $c$

Using        $\lambda \times \nu = c = constant$
$\implies$ If frequencies of the pure spectral colours increase then their wavelength will decrease.

Multiple choice physics spectra the electromagnetic spectrum electromagnetic spectrum electromagnetic waves

According to the electromagnetic spectrum. Which of the following is NOT a pure spectral colour?

  1. white

  2. violet

  3. red

  4. blue

  5. yellow
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Electromagnetic spectrum of visible light :     $VIBGYOR$

VIBGYOR stands for Violet, Indigo, Blue, Green, Yellow, Orange and Red.
These are pure spectral colours but not white. Infact, white colour is formed due to  interference of all these 7 colours.

Multiple choice physics spectra the electromagnetic spectrum electromagnetic spectrum electromagnetic waves

Which of the following light has the combination of all frequencies of visible light ?

  1. white light

  2. black light

  3. ultraviolet light

  4. infrared light

  5. transparency
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The visible light contains 7 colours  :  Violet, indigo, Blue, Green, Yellow, Orange and Red.

White colour is formed by the interference of all 7 colours, thus white light has the combination of all frequencies of visible light.

Multiple choice physics spectra the electromagnetic spectrum electromagnetic spectrum electromagnetic waves

Identify which of the following is NOT a source of visible light?

  1. red-hot metal

  2. cool metal

  3. fluorescent bulb

  4. the Sun

  5. fire
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When the electrons in the atom are excited, for example by being heated, the additional energy pushes the electrons to higher energy orbits. When the electrons fall back down and leave the excited state, energy is re-emitted in the form of a photon.

Thus the hot objects release photons that have energies lying in the visible region. However photons from cool metal do not have energy enough to lie in visible region.

Multiple choice physics spectra the electromagnetic spectrum electromagnetic spectrum electromagnetic waves

If a particular electromagnetic wave has the highest frequencies among the other electromagnetic waves then it should have the smallest

  1. wavelengths

  2. speeds

  3. amplitudes

  4. energies

  5. periods
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Electromagnetic waves travel with constant speed equal to that of light  i.e  $v =c= constant$

For EM waves       $\lambda \times \nu = c =$ constant
Thus waves with highest frequency will have smallest wavelength.