Wavelength

Q.

Define the following terms in relation to a wave :

(a) amplitude, (b) frequency, (c) wavelength, and (d) wave velocity.

Q.

Length of a vibrating string is halved. What will happen to its frequency?

1. Its frequency will become one fourth of the original

2. Its frequency will be doubled

3. Its frequency will be halved

4. Its frequency will be tripled

5. Its frequency will remain unaffected

Q.

The distance between a compression and the next rarefaction will be:

($\lambda$ indicates the wavelength of the wave)

1. λ/8

2. λ/2

3. λ/4

4. λ/16

Q. The radiation suffering the maximum deflection in a magnetic field is :

1. α-particles
   
2. β-particles
3. γ-radiations
   
4. X-rays

Q.

Distance from one compression to the nearest rarefaction is called a wavelength.

1. True
2. False

Q.

Can coherent waves have different amplitudes?

Q.

The diagram in the figure shows three ways in which the string of length l in an instrument can vibrate.

(a) Which of the diagram shows the principal note?

(b) Which vibration has the frequency four times that of the first?

(c) Which vibration is of longest wavelength?

(d) What is the ratio of frequency of vibrations in diagram (i) and (ii)?

Q.

In young’s double-slit experiment, the fringe width observed is β. if the frequency of the source is tripled, then new fringe width will become

Q. The distance between a compression and the immediate next rarefaction of a longitudinal wave is:
($\lambda$ denotes wavelength)

1. $\frac{\lambda }{4}$
2. $2\lambda$
3. $\frac{\lambda }{8}$
4. $\frac{\lambda }{2}$

Q. Assertion :Microwaves are better carrier of signals than the optical waves. Reason: Microwaves move faster than optical waves.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect

Q. In a transverse wave, a particle makes 100 ocsillations in 10 seconds. Its frequency is:

1. 100 Hz.
2. 50 Hz.
3. 5 Hz.
4. 10 Hz.

Q. The speed of a light is 310(10) nm/sec What is the value of wavelength in nm of quantum light with frequency of6101010 1010/sec.

Q. The minimum value of the refractive index for a ${90}^{\circ }-{45}^{\circ }-{45}^{\circ }$ prism that is used to deviate a beam by ${90}^{\circ }$ by the phenomenon of total internal reflection is ________.

1. $2$
2. $1$
3. $\sqrt{2}$
4. $0$

Q.

If the frequency of a wave is doubled, its wavelength

1. becomes doubled

2. remains same

3. is halved

4. none of these

Q.

The S.I. unit of wavelength(λ) is:

1. Decible

2. Metre

3. m/s

4. sec

Q. The distance between any two consecutive compressions and rarefactions is termed as:

1. frequency
2. amplitude
3. wavelength
4. time period

Q.

a type of electromagnetic wave has wavelength 50A ?

Q. In the case of refraction of light :
a) Frequency changes
b) Speed changes
c) Wavelength changes

1. b and c are correct
2. a is correct
3. a, b, c are correct
4. a and b are correct

Q. The distance between two consecutive compressions or rare factions in a wave of wavelength, $\lambda$ is

1. $2\lambda$
2. $\lambda /2$
3. $\lambda /4$
4. $\lambda$

Q. When light is refracted, which of the following does not change?
(a) Wavelength
(b) Frequency
(c) Velocity
(d) Amplitude

Q.

the wave length coming from sodium dource is 589 nm. what will be its wavelength in water?

Q.

Represent graphically by two separate diagrams in each case-

(iii) Two sound waves having different amplitudes and also different wavelength.

Q.

The wave number of a beam of light is 800cm-1. What is the wavelength of light in nanometers? Also find out frequency of light.

Q. Three resonant frequencies of a string are 90, 150 and 210 Hz. (a) Find the highest possible fundamental frequency of vibration of this string. (b) Which harmonics of the fundamental are the given frequencies? (c) Which overtones are these frequencies? (d) If the length of the string is 80 cm, what would be the speed of a transverse wave on this string?

Q.

The distance between a compression and the immediate next rarefaction of a longitudinal wave is:

1. $\frac{\lambda }{4}$

2. 2λ

3. $\frac{\lambda }{2}$

4. $\frac{\lambda }{8}$

Q. An engine is moving on a circular path of radius 100 metre with a speed of 20 metre per second. The frequency observed by an observer standing stationary at the centre of circular path when the engine blows a whistle of frequency 500 Hz is

1. more than 500 Hz
2. less than 500 Hz
3. no sound is heard
4. 500 Hz

Q.

Yellow light is emitted from a solid lamp has a wavelength of 580 nm. Calculate the frequency and wave number of the yellow light.

Q. what is the wavelength of electromagnetic wave whose frequency is 10^12hz name the electromagnetic wave (speed of light is 3x10^8 m/s)