7/25/2019 16- Waves

1/15

Q1)Domino Toppling is one entry in the Guinness Book

of World Records. The eent consists of lining up !n

incredi"le num"er of dominoes !nd then letting them topple#

one !fter !nother. $s the distur"!nce th!t prop!g!tes !long the

line of dominoes tr!nserse# longitudin!l# or p!rtly "oth%

1)tr!nserse

&)longitudin!l

')p!rtly "oth

Q&) Which of the follo(ing !re tr!nserse (!es *!)+n oce!n

(!e rolling to(!rd ,!nt! -ru "e!ch# *")The sound of one (h!le

c!lling !nother (h!le under (!ter/ *c)+ pulse sent do(n !

stretched rope "y sn!pping one end of it.

1)! &)" ')c

0)! !nd c )!# "# !nd c

Q3)Consider the following waves:

The "wave" made by fans at sports events

waves on the surface of a lake Music in the auditorium

TV signals transmitting pictures

How many of the above four are transversewaves?

7/25/2019 16- Waves

2/15

1)1 2)2 3)3 4)4 5)None

7/25/2019 16- Waves

3/15

Q4)Which one of the following is most likely to be impossible?

1)Transverse waves in a fluid

2)Longitudinal waves in a fluid

3)Transverse waves in a solid

4)Longitudinal waves in a solid5)Waves in a vacuum (no medium)

Q)By sh!king one end of ! stretched string# ! single pulseis gener!ted. The tr!eling pulse c!rries

1)energy.

&)momentum.

')energy !nd momentum.

0)neither of the t(o.

Q2)+n o"3ect th!t completes 144 i"r!tions in seconds h!s !period of

1)4. second.

&)1 second.

')& seconds.

0)5one of the !"oe choices !re correct.

7/25/2019 16- Waves

4/15

Q6)+ periodic (!e is produced on ! stretched string. Which one

of the follo(ing properties is not rel!ted to the speed of the (!e%

1)fre7uency

&)!mplitude

')period0)(!elength

)tension in the string

Q8)Which one of the follo(ing st!tements concerning (!es is

f!lse%

1)+ (!e c!n h!e "oth tr!nserse !nd longitudin!l components.

&)+ (!e c!rries energy from one pl!ce to !nother.

')+ (!e does not result in the "ulk flo( of the m!teri!l of its

medium.

0)+ (!e is ! tr!eling distur"!nce.

)+ tr!nserse (!e is one in (hich the distur"!nce is p!r!llel to

the direction of tr!el.

Q9)$f the fre7uency of (!e is dou"led# (h!t ch!nge

(ill occur in *!)its speed% *")$n its (!elength%

1)*!) dou"le *") dou"le

&)*!) dou"le *") cut in h!lf

')*!) rem!in the s!me *") dou"le

0)*!) rem!in the s!me *") cut in h!lf

)*!) cut in h!lf *") rem!in the s!me

7/25/2019 16- Waves

5/15

Q14)+ source of fre7uencyfsends (!es of (!elength :

tr!eling (ith speed in some medium. $f the fre7uency is

ch!nged fromfto &f# then the ne( (!elength !nd ne( speed !re

*respectiely)

1) & &) ;&

') &

0) ;&

) ;& &

Q11)$f the (!es !re going !t the s!me speed# (hich (!e

h!s the gre!test period of oscill!tion%

1)$

&)$$

')$$$0)$# t) C ymsin*k> E t ). +t time t C 4 the

point !t > C 4 h!s ! elocity of 4 !nd ! positie displ!cement. The

ph!se const!nt is

1);0 r!di!ns

&);& r!di!ns

')r!di!ns

0)';& r!di!ns

)none of the !"oe

Q&4)The displ!cement of ! string c!rrying ! tr!eling sinusoid!l

(!e is gien "y

y*>#t) C ymsin*k>t)

+t time t C 4 the point !t > C 4 h!s ! displ!cement of 4 !nd is

moing in the positie y direction. The ph!se const!nt is

1)0F &)94F ')1'F

0)184F )&64F

Q&1)+ rope of m!ss m is h!nging do(n from the ceiling. 5othingis !tt!ched to the loose end of the rope. + tr!nserse (!e is

tr!eling on the rope. +s the (!e tr!els up the rope# does the

speed of the (!e incre!se# decre!se# or rem!in the s!me%

1)incre!se

&)decre!se

7/25/2019 16- Waves

9/15

')rem!in the s!me

Q&&)When ! 144? oscill!tor is used to gener!te ! sinusoid!l

(!e on ! cert!in string the (!elength is 14 cm. When the

tension in the string is dou"led the gener!tor produces ! (!e (ith

! fre7uency !nd (!elength of

1)101 ? !nd &4 cm

&)101 ? !nd 10 cm

')144 ? !nd &4 cm

0)144 ? !nd 10 cm

) 4 ? !nd 10 cm

Q23)Two piano strings have the same tension, are made from the

same material, and have the same length, but string B is thicker

(larger diameter) than string A. The pitch from string B will be

1)lower than

2)higher than

3)the same as

4)not enough information

that from string A.

Q&0)The tension in ! guit!r string is dou"led. ?o( does thefre7uency of oscill!tion ch!nge%

1)it incre!ses "y ! f!ctor of &

&)it decre!ses "y ! f!ctor of &

')it incre!ses "y ! f!ctor of &

7/25/2019 16- Waves

10/15

0)it decre!ses "y ! f!ctor of &

)none of the !"oeQ&)+ long string is constructed "y 3oining the ends of t(o shorter

strings. The tension in the strings is the s!me "ut string $ h!s 0

times the line!r m!ss density of string $$. When ! sinusoid!l (!e

p!sses from string $ to string $$

1)the fre7uency decre!ses "y ! f!ctor of 0

&)the fre7uency decre!ses "y ! f!ctor of &

')the (!e speed decre!ses "y ! f!ctor of 0

0)the (!e speed decre!ses "y ! f!ctor of &

)the (!e speed incre!ses "y ! f!ctor of &

Q&2)T(o strings# one thick !nd the other thin# !re connected to

form one long string. + (!e tr!els !long the string !nd p!sses

the point (here the t(o strings !re connected. Which of the

follo(ing ch!nge*s) !t th!t point

1)fre7uency

&)period

')prop!g!tion speed

0)(!elength

Q&6)The follo(ing four (!es !re sent !long strings (ith thes!me line!r densities. R!nk the (!es !ccording to the tensions in

the strings !long (hich they tr!el# gre!test first

*1) y1C *' mm) sin*> E 't) *') y'C *1 mm) sin*0> Et)

*&) y&C *2 mm) sin*&> E t) *0) y0C *& mm) sin*> E &t)

7/25/2019 16- Waves

11/15

1) ' # 1C0 &) 1# 0# 1C' ') 1# 0# '

0) '# 0# 1 ) none

Q&8)+ string th!t is stretched "et(een fi>ed supports sep!r!ted "y

6.4 cm h!s reson!nt fre7uencies of 0&4 !nd '1 ? (ith no

intermedi!te reson!nt fre7uencies. Wh!t is the (!e speed of

the string%

1)68.6 m;s &)16. m;s ')&'2 m;s

0)06& m;s )none of the !"oe

Q&9)+ tr!nserse (!e is tr!eling (ith ! speed of '44 m;s on !

horiont!l string. $f the tension in the string is incre!sed "y ! f!ctorof four# (h!t is the speed of the (!e%

1)6 m;s

&)14 m;s

')'44 m;s

0)244 m;s

)1&44 m;s

Q30)A weight is hung over a pulley and attached to a string

composed of two parts, each made of the same material but one

having four times the diameter of the other. The string is plucked

so that a pulse moves along it, moving at speed v1in the thick partand at speed v&in the thin part.

What is v1/ v&?

1)1

2)2

7/25/2019 16- Waves

12/15

3)

4)

7/25/2019 16- Waves

13/15

Q'1)$n the st!nding (!e sho(n# (h!t is its

!mplitude%

1)04 centimeters

&)&4 centimeters')14 centimeters

Q'&)$n the st!nding (!e sho(n# ho( m!ny nodes !rethere%

1)'

&)0

')0)2

Q'')Which one of the follo(ing st!tements is true concerning thepoints on ! string th!t sust!in ! st!nding (!e p!ttern%

1)+ll points i"r!te (ith the s!me energy.

&)+ll points undergo the s!me displ!cements.

')+ll points i"r!te (ith different fre7uencies.

0)+ll points i"r!te (ith different !mplitudes.

)+ll points undergo motion th!t is purely longitudin!l.

7/25/2019 16- Waves

14/15

Q34)A string is clamped at both ends and then plucked so that it

vibrates in a standing mode between two extreme positions a and c.

Let upward motion correspond to positive velocities. When the

string is in position b, the instantaneous velocity of points along

the string is...

1)4 eery(here. &) eery(here. 3)- everywhere.

4)depends on position.

Q')+ string of length 144 cm is held fi>ed !t "oth ends !nd

i"r!tes in ! st!nding (!e p!ttern. The (!elengths of the

constituent tr!eling (!es -+55HT "e

1)044 cm

&)&44 cm')144 cm

0)22.6 cm

)4 cm

Q'2)$f you set up the seenth h!rmonic on ! string# is there

! node# !ntinode# or some intermedi!te st!te !t the

midpoint%

1)node

&)!ntinode

')intermedi!te st!te

!

"

c

7/25/2019 16- Waves

15/15

Q'6)$f you set up the seenth h!rmonic on ! string# *!) ho(

m!ny nodes !re present# !nd *") is there ! node# !ntinode# or

some intermedi!te st!te !t the midpoint%

1) *!) 6 *") node

&) *!) 6 *") !ntinode') *!) 8 *") node

0) *!) 8 *") !ntinode

) *!) 8 *") some intermedi!te st!te

Q38)A string on an instrument plays an A (440 Hz) when plucked.

If you put your finger down in the middle of the string, and then

pluck, you are mostly likely to hear

1)A an octave higher (880 Hz)

2)A, an octave lower (220 Hz)

3)Same tone4)Some entirely different note.

Q39)A string vibrates with a natural fundamental frequency of

220 Hz, with a wavelength of 2m. Besides 220 Hz, which of the

following are "resonant frequencies" which you might also faintly

detect?

i) 110 Hz ii) 330 Hz iii) 440 Hz

1)i only 2)ii only 3)iii only

0)i !nd ii )!ll three