Nature of Electromagnetic Radiation

Q.

What are 3 characteristics of electromagnetic waves?

Q.

Calculate (a) wavenumber and (b) frequency of yellow radiation having wavelength 5800 $\mathring{A}$.

1. $1.724\times {10}^{12}c{m}^{-1}and5.172\times {10}^4{s}^{-1}$

2. $1.724\times {10}^{12}c{m}^{-1}and5.172\times {10}^2{s}^{-1}$

3. $1.724\times {10}^{4}c{m}^{-1}and5.172\times {10}^{12}{s}^{-1}$

4. $1.724\times {10}^{4}c{m}^{-1}and5.172\times {10}^{14}{s}^{-1}$

Q. Newton’s corpuscular theory was able to explain which of the following phenomenon?

1. Interference
2. Polarisation
3. Diffraction
4. Refraction

Q.

Yellow light emitted from a sodium lamp has a wavelength (λ) of 580 nm. Calculate the frequency (ν) and wave number ( $\overline{V}$ ) of the yellow light.

Q.

What are the 4 main properties of electromagnetic waves?

Q. The correct sequence of frequency for electromagnetic radiations in the electromagnetic spectrum is:

1. Radio waves > Microwaves > UV rays > X-rays
2. X-rays > UV rays > Microwaves > Radio waves
3. Radio waves > Microwaves > X-rays > UV rays
4. UV rays > X-rays > Radio waves > Microwaves

Q. The shortest wavelength in H spectrum of Lyman series when $R_H=109678c{m}^{-1}$ is

1. 1215.67 Å

2. 1127.30 Å

3. 911.7 Å

4. 1002.7 Å

Q. The frequency of radiation with wavelength 480 nm is:

1. $6.25\times {10}^{14}Hz$
2. $6.25\times {10}^{13}Hz$
3. $6.25\times {10}^{12}Hz$
4. $6.25\times {10}^{11}Hz$

Q.

Calculate the wavelength, frequency and wave number of a light wave whose period is 2.0 × ${10}^{–10}$ s.

Q.

What is Zeeman effect?

Q.

The ionization energy of hydrogen atom is -13.6 eV. The energy required to excite the electron in a hydrogen atom from the ground state to the first excited state is: (Avogadro's constant =6.022 × 10²³)

1. 1.69 × 10^-20 J

2. 1.69 ×10 ²⁵ J

3. 1.69 × 10^-23 J

4. 1.69 ×10 ²³ J

Q.

A galaxy is moving away from the earth at a speed of $286km/s$. The shift in the wavelength of a redline at $630nm$ is $X\times {10}^{-10}m$. The value of $X$, to the nearest integer, is [Take the value of speed of light, $c=3\times {10}^{8}m{s}^{-1}$]

Q. Photon of which light has maximum energy

1. Red
2. Blue
3. Violet
4. Green

Q. What electronic transition in the $H{e}^{+}$ ion would emit the radiation of the same wavelength as that of the first Lyman transition of hydrogen atom ?

1. $2\to 1$
2. $4\to 2$
3. $3\to 1$
4. $2\to 4$

Q.

A gas absorbs a photon of 355 nm and emits two wavelengths. If one of the emission is at 680 nm, the other is at:

1. 518 nm

2. 743 nm

3. 1035 nm

4. 325 nm

Q.

What are some uses for microwave radiation?

Q.

Arrange the following type of radiations in increasing order of frequency: (a) radiation from microwave oven (b) amber light from traffic signal (c) radiation from FM radio (d) cosmic rays from outer space and (e) X-rays.

Q. A 600 W mercury lamp emits a monochromatic radiation of wavelength 331.3 nm. How many photons are emitted from the lamp per second?
$h=6.626\times {10}^{-34}\text{Js};\text{velocity of light =}3\times {10}^8{\text{ms}}^{-1}$

1. ${10}^{21}$
2. ${10}^{22}$
3. ${10}^{20}$
4. ${10}^{19}$

Q. The ground state energy of hydrogen atom is -13.6 eV. The energy of second excited state of $H{e}^{+}$ ion in eV is

1. -6.04
2. -27.2
3. -54.4
4. -3.4

Q.

An electron and proton possess same K.E., how will their momentum be related?

Q.

The speed of electromagnetic waves in air is

1. $3\times {10}^{5}km/s$

2. $3\times {10}^{6}km/s$

3. $3\times {10}^{7}km/s$

4. $3\times {10}^{8}km/s$

Q. Calculate energy of 2 moles of photons of radiation whose frequency is $5\times {10}^{14}Hz$

1. $3.313\times {10}^{-19}J$
2. $6.626\times {10}^{-19}J$
3. $3990.2kJmo{l}^{-1}$
4. $6790.2kJmol-1$

Q. A certain radio station broadcasts on a frequency of 1890 kHz (kilohertz). What is the wavelength of the electromagnetic radiation broadcasted by the station?

1. 158.7 m
2. 100.5 m
3. 135.9 m
4. 88.2 m

Q.

A 100 Watt bulb emits monochromatic light of wavelength 400 nm. Calculate the number of photons emitted per second by the bulb.

1. 4 $\times$ ${10}^{20}$ $s^{-1}$

2. 2 $\times$ ${10}^{20}$ $s^{-1}$

3. 8 $\times$ ${10}^{20}$ $s^{-1}$

4. 1$\times$ ${10}^{20}$ $s^{-1}$

Q. The certainty in velocity of an electron present in the nucleus of diameter 10 to the power -15 meter hypothetically should be approximately?

Q. Statement - 1: The difference between two adjacent crests is called wavelength.
Statement - 2: Frequency is defined as number of waves that pass a given point in one second.
Statement - 3: The maximum displacement shown by a point on a wave measured from its equivalent position is called wave number.

1. FTT
2. TTF
3. FFT
4. TTT

Q. de Broglie wavelength of charged particles depends on:

1. All above
2. Nature of particle
3. Kinetic energy of particle
4. Mass of particle

Q. Stark effect refers to:

1. "Ejection of photoelectron from a metal surface"
2. "K-electron capture"
3. "Splitting of spectral lines in electric field"
4. Splitting of spectral lines in magnetic field

Q.

Two points on a traveling wave having a frequency $600Hz$ and velocity $300\frac{m}{s}$ are $60°$ out of phase, then the minimum distance between the two points is

1. $0.3$

2. $0.083$

3. $0.25$

4. $0.4$

Q. The angular momentum of the allowed orbits in a $H-$ like species is integral multiple of:

1. $\frac{h}{\pi }$
2. $\frac{h}{2\pi }$
3. $h\pi$
4. $\pi$