TBSE Class 11 Model Question Paper for 2021 Physics

Model Question
Class - XI : Physics : 70 Marks : 2020-2021
!Ó˲yàÈüÈܲ : ≤Ã!ï˛!ê˛ ≤Èϟ¿Ó˚ ÙylÈüÈ1 : 1 x 20 = 20
1ä ˛y = A Sin (wt – kx) (in m) - ~•z §Ù#ܲÓ˚î!ê˛ˆÏï˛ x-ˆÜ˛ m ~ܲˆÏܲ ~ÓÇ t-ˆÜ˛ s ~ܲˆÏܲ ≤Ãܲy¢ ܲÓ˚y •ˆÏÎ˚ˆÏSÈ–
w ~ÓÇ k ~Ó˚ Ùyey §Ù#ܲÓ˚î!ê˛ ˆ°á–
2ä ~ܲ!ê˛ Ó›ˆÏܲ í˛zÕ‘¡∫˲yˆÏÓ í˛zˆÏô≈ í˛z͈ϫ˛˛õ ܲÓ˚y •ˆÏ°y ~ÓÇ Ó›!ê˛ xyÓyÓ˚ í˛z͈ϫ˛˛õl !Ó®%ˆÏï˛ !Ê˛ˆÏÓ˚ ~ˆÏ°y– ~•z Ó›!ê˛Ó˚ à!ï˛Ó˚
ˆÓàÈüȧÙÎ˚ ˆ°á!ã˛e!ê˛ xAܲl ܲÓ˚–
D xÌÓy
~ܲ!ê˛ òy°yˆÏlÓ˚ SÈyò ˆÌˆÏܲ ~ܲ!ê˛ Ó›ˆÏܲ xl%Ë)˛!Ùܲ˲yˆÏÓ !lˆÏ«˛˛õ ܲÓ˚y •ˆÏ°y– Ó›!ê˛Ó˚ à!ï˛ˆÏÓˆÏàÓ˚ xl%Ë)˛!Ùܲ í˛z˛õyÇ¢ G
í˛z°¡∫ í˛z˛õyLjϢÓ˚ çlƒ ˆÓàÈüȧÙÎ˚ ˆ°á!ã˛e!ê˛ xAܲl ܲÓ˚–
3ä ~ܲ!ê˛ !l!ò≈T˛ ò)Ó˚c ˆÌˆÏܲ 600 ˆÜ˛yˆÏî ~ܲ!ê˛ ˆày°yˆÏܲ !lˆÏ«˛˛õ ܲˆÏÓ˚ ˆÜ˛yˆÏly ~ܲ!ê˛ ê˛yˆÏà≈ê˛ˆÏܲ xyâyï˛ Ü˛Ó˚y ÎyÎ˚– x˛õÓ˚
ˆÜ˛yl‰ ˆÜ˛yˆÏî ˆày°y!ê˛ˆÏܲ !lˆÏ«˛˛õ ܲÓ˚ˆÏ° !l!ò≈T˛ ò)ˆÏÓ˚Ó˚ ˙ ê˛yˆÏà≈ê˛ˆÏܲ xyâyï˛ Ü˛Ó˚y ÎyˆÏÓ⁄
4ä Î!ò ~ܲ!ê˛ à!ï˛¢#° ܲîyÓ˚ cÓ˚î §ÙˆÏÎ˚Ó˚ §yˆÏ˛õˆÏ«˛ ˛õ!Ó˚Óï≈˛l¢#° •Î˚ ï˛ˆÏÓ cÓ˚îÈüȧÙÎ˚ ˆ°á!ã˛ˆÏe ˆÜ˛yˆÏly §ÙÎ˚ÈüÈxÓܲyˆÏ¢
xhs˝Ë%≈˛=˛ xM˛ˆÏ°Ó˚ ˆ«˛eÊ˛° ܲ# !lˆÏò≈¢ ܲˆÏÓ˚⁄
5ä A = ɵi + 2 ɵj + 2kɵ ~ÓÇ B = ɵi − ɵj + nkɵ ˆË˛QÓ˚mÎ˚ ˛õÓ˚flõˆÏÓ˚Ó˚ í˛z˛õÓ˚ °¡∫ •ˆÏ° n ~Ó˚ Ùyl Ü˛ï˛ !lî≈Î˚ ܲÓ˚–
6ä !ÓÓ˚yÙ ˆÜ˛yî G â£Ï≈î ˆÜ˛yˆÏîÓ˚ ÙˆÏôƒ §¡õÜ≈˛ !ܲÓ˚)˛õ ⁄
7ä m ˲ˆÏÓ˚Ó˚ ~ܲ!ê˛ Ó› í˛z°¡∫ï˛ˆÏ° Ó,_yܲyÓ˚ ˛õˆÏÌ §Ó≈!l¡¨ ˆÓˆÏà â)î≈l¢#° •ˆÏ° ˙ ˛õˆÏÌÓ˚ §ˆÏÓ≈yFã˛ !Ó®%ˆÏï˛ Ó›!ê˛Ó˚ xy˛õyï˛ÈüÈGçl
Ü˛ï˛ •ˆÏÓ⁄
8ä ~ܲ!ê˛ •y°Ü˛y Ó› G ~ܲ!ê˛ xˆÏ˛õ«˛yÜ,˛ï˛ ˲yÓ˚# Ó› ~ܲ•z à!ï˛¢!=˛ !lˆÏÎ˚ ã˛°ˆÏSÈ– Ó› ò%!ê˛ˆÏܲ ~ܲ•z Ó° ≤ÈÏÎ˚yà ܲˆÏÓ˚
!fiÌï˛yÓfiÌyÎ˚ xyly •°– Ó›ò%!ê˛Ó˚ ÙˆÏôƒ ˆÜ˛yl‰!ê˛ Ü˛Ù ò)Ó˚ˆÏc ~ˆÏ§ ˆÌˆÏÙ ÎyˆÏÓ⁄
9ä çí˛¸ï˛yÈüȺyÙˆÏܲÓ˚ ï˛yͲõÎ≈ ܲ#⁄
D xÌÓy
Óƒy!Ó!ê˛Ç !ܲ⁄
10ä ~ܲ!ê˛ xylï˛ ï˛ˆÏ°Ó˚ í˛z˛õÓ˚ ˆÌˆÏܲ ~ܲ•z Ó˚ܲˆÏÙÓ˚ ò%!ê˛ ˆã˛y. !fiÌÓ˚ xÓfiÌy ˆÌˆÏܲ Îyey ¢%Ó˚% ܲÓ˚°– ~ˆÏòÓ˚ ÙˆÏôƒ ≤ÃÌÙ!ê˛ ly
•í˛¸!ܲˆÏÎ˚ §¡õ)î≈˲yˆÏÓ à!í˛¸ˆÏÎ˚ ˆà° xyÓ˚ !mï˛#Î˚ ly à!í˛¸ˆÏÎ˚ §¡õ)î≈˲yˆÏÓ •í˛¸!ܲˆÏÎ˚ ˆà°– í˛z˲Î˚ ˆ«˛ˆÏe Îy!sfܲ ¢!=˛ xlƒ ˆÜ˛yˆÏly
¢!=˛ˆÏï˛ x˛õ!ã˛ï˛ •Î˚!l ôˆÏÓ˚ !lˆÏ° ˆã˛y. ò%!ê˛Ó˚ ÙˆÏôƒ ˆÜ˛yl!ê˛ xyˆÏà xylï˛ï˛ˆÏ°Ó˚ ˛õyòˆÏòˆÏ¢ ˆ˛õÔÑSȈÏÓ⁄
11ä ˛õ,!ÌÓ#˛õ,¤˛ ˆÌˆÏܲ h í˛zFã˛ï˛yÎ˚ ~ÓÇ ˛õ,!ÌÓ#˛õ,¤˛ ˆÌˆÏܲ d à˲#Ó˚ï˛yÎ˚ g-~Ó˚ ˛õ!Ó˚Óï≈˛ˆÏlÓ˚ Ùyl §Ùyl •ˆÏ° h ~ÓÇ dÈüÈ~Ó˚ ÙˆÏôƒ
§¡õÜ≈˛ !lî≈Î˚ ܲÓ˚– ôˆÏÓ˚ lyG ˆÎñ h << R, ˆÎáyˆÏl R •° ˛õ,!ÌÓ#Ó˚ Óƒy§yô≈– A
B
12ä ò%!ê˛ ˛õòyÌ≈ A ~ÓÇ B ~Ó˚ ˛õ#í˛¸îÈüÈ!ÓÜ,˛!ï˛ ˆ°á!ã˛e!ê˛ !lˆÏã˛ ˆòáyˆÏly • °–
˛õ#í˛¸î

~ˆÏòÓ˚ ÙˆÏôƒ ˆÜ˛yl ˛õòyÌ≈!ê˛ x!ôܲï˛Ó˚ ò,ì˛¸–

È!ÓÜ,˛!ï˛
13ä 1cm Óƒy§yˆÏô≈Ó˚ ~ܲ!ê˛ lˆÏ°Ó˚ ˆË˛ï˛Ó˚ !òˆÏÎ˚ 6cm / s ˆÏÓˆÏà ç° ≤ÃÓy!•ï˛ •ˆÏFSÈ– âˆÏÓ˚Ó˚ ï˛y˛õÙyeyÎ˚ çˆÏ°Ó˚ §ywï˛y à%îyAܲ
0.01 Poise •ˆÏ° çˆÏ°Ó˚ ≤ÃÓyˆÏ•Ó˚ ≤ÃÜ,˛!ï˛ !lÓ˚)˛õî ܲÓ˚–
14ä 40C ï˛y˛õÙyeyÓ˚ ç° !òˆÏÎ˚ ~ܲ!ê˛ Ó#ܲyÓ˚ˆÏܲ ܲyîyÎ˚ ܲyîyÎ˚ ˛õ)î≈ ܲÓ˚y •°– !ÓܲyÓ˚!ê˛ˆÏܲ àÓ˚Ù Ü˛Ó˚y •ˆÏ° !ܲÇÓy ë˛yu˛y ܲÓ˚y
•ˆÏ° !ÓܲyˆÏÓ˚Ó˚ í˛z˛õ!ã˛ˆÏÎ˚ ˛õˆÏÓ˚ ˆÜ˛l⁄
15ä ï˛y˛õà!ï˛!ÓòƒyÓ˚ ≤ÃÌÙ §)e!ê˛ !ÓÓ,ï˛ Ü˛Ó˚–
16ä ï˛y˛õà!ï˛!ÓòƒyÓ˚ ¢)lƒï˛Ù §)ˆÏeÓ˚ §y•yˆÏ΃ ï˛y˛õÙyeyÓ˚ ôyÓ˚îy òyG–

17ä §ÇÜ˛ê˛ ï˛y˛õÙyey Ó°ˆÏï˛ !ܲ Ó%V˛⁄
18ä ˆÜ˛yl‰ xÓfiÌyˆÏl ~ܲ!ê˛ §Ó˚°ˆÏòy°à!ï˛§¡õߨ ˆÜ˛yˆÏly ܲîyÓ˚ à!ï˛¢!=˛ ܲîy!ê˛Ó˚ §ˆÏÓ≈yFã˛ à!ï˛¢!=˛Ó˚ xˆÏô≈ܲ •ˆÏÓ⁄
19ä ˆÜ˛yˆÏly !ÓFS%ÈÓ˚ܲ ÙyôƒˆÏÙÓ˚ ÙˆÏôƒ !òˆÏÎ˚ ï˛Ó˚Aà !ÓhflÏyˆÏÓ˚Ó˚ §ÙÎ˚ ï˛Ó˚ˆÏAàÓ˚ xyÜ,˛!ï˛ !ÓÜ,˛ï˛ •Î˚ ˆÏܲl⁄
20ä ò%!ê˛ ˆ§ï˛yÓ˚ ï˛yÓ˚ A ~ÓÇ BÈüȈï ÚôyÛ §%Ó˚!ê˛ §yÙylƒ §%Ó˚ ˛õyÌ≈ˆÏܲƒ ˆÓˆÏç 5Hz ܲ¡õyˆÏAܲÓ˚ fl∫Ó˚ܲ¡õ §,!T˛ ܲˆÏÓ˚– ~ÓyÓ˚ B
ï˛yˆÏÓ˚Ó˚ ê˛yl §yÙylƒ Óyí˛¸yˆÏly •°– ~Ó˚ Ê˛ˆÏ° ï˛yÓ˚mˆÏÎ˚Ó˚ ܲ¡õˆÏlÓ˚ òÓ˚%î §,T˛ fl∫Ó˚ܲ¡õ ܲˆÏÙ 3Hz •Î˚– A ï˛yˆÏÓ˚Ó˚ ܲ¡õyAܲ
427 •ˆÏ° B ï˛yˆÏÓ˚Ó˚ ܲ¡õyAܲ ≤Ã̈ÏÙ Ü˛ï˛ !SÈ°⁄
!Ó˲yàÈüÈá : ≤Ã!ï˛!ê˛ ≤Èϟ¿Ó˚ Ùyl 2 : 2 x 7 = 14
21ä ÚxÓyˆÏô ˛õï˛l¢#° Ó›Ó˚ Gçl ¢)lƒ •Î˚Û ÈüüüÈ Óƒyáƒy òyG–
3
22ä 0.5 kg ˲ˆÏÓ˚Ó˚ ~ܲ!ê˛ Ó› §Ó˚° ˆÓ˚áy ÓÓ˚yÓÓ˚ V= α . × 2 à!ï˛ˆÏÓà !lˆÏÎ˚ ã˛°ˆÏSÈñ ˆÎáyˆÏl , α = 5m −1s −1
x = 0 xÓfiÌyl ˆÌˆÏܲ x = 2m xÓfiÌyˆÏl Ó›!ê˛Ó˚ §Ó˚ˆÏîÓ˚ çlƒ ˆÙyê˛ ÓˆÏ°Ó˚ myÓ˚y Ü,˛ï˛Ü˛yÎ≈ Ü˛ï˛ •ˆÏÓ⁄
D xÌÓy
7 ms ˆÓˆÏà l#ˆÏã˛Ó˚ !òˆÏܲ à!ï˛¢#° ~ܲ!ê˛ !°Ê˛ˆÏê˛Ó˚ SÈyò ˆÌˆÏܲ 0.3 kg ˲ˆÏÓ˚Ó˚ ~ܲ!ê˛ ˆÓyŒê˛ !°Ê˛ˆÏê˛Ó˚ ˆÙˆÏV˛ˆÏï˛ ˛õí˛¸ˆÏ°y–
–1

ˆÙˆÏV˛ˆÏï˛ ˛õí˛¸yÓ˚ ˛õÓ˚ Ó›!ê˛ ≤Ã!ï˛!«˛Æ ly •ˆÏ° ~•z §ÇâyˆÏï˛ í˛zͲõy!òï˛ ï˛y˛õ Ü˛ï˛ •ˆÏÓ⁄ ôˆÏÓ˚ lyG ˆÎñ !°Ê˛ˆÏê˛Ó˚ í˛zFã˛ï˛y 3m–
!°Ê˛ê˛!ê˛ !fiÌÓ˚ xÓfiÌyÎ˚ ÌyܲˆÏ° ˆï˛yÙyÓ˚ í˛z_ˆÏÓ˚Ó˚ ܲ# ˛õ!Ó˚Óï≈˛l •ˆÏÓ⁄
23ä •%Ó•% ~ܲ•z Ó˚ܲˆÏÙÓ˚ ò%!ê˛ Ó›Ó˚ ÙˆÏôƒ ˛õ)î≈ÈüÈ!fiÌ!ï˛fiÌy˛õܲ §Çâ£Ï≈ âê˛ˆÏ°y– Ó› ò%!ê˛Ó˚ ~ܲ!ê˛ ≤ÃyÌ!Ùܲ xÓfiÌyÎ˚ !fiÌÓ˚ ÌyܲˆÏ°
ˆòáyG ˆÎñ §ÇâˆÏ£Ï≈Ó˚ ˛õˆÏÓ˚ Ó›ò%!ê˛ §ÙˆÏܲyˆÏî à!ï˛¢#° •ˆÏÓ⁄
24ä Ù•yܲ£Ï#≈Î˚ ˆ«˛e ≤ÃyÓ°ƒ Ó°ˆÏï˛ !ܲ ˆÓyV˛ ⁄ ~Ó˚ ~ܲܲ !ܲ ⁄
25ä §Ùyl ôyÓ˚ܲc !Ó!¢T˛ ò%!ê˛ ˆã˛y. A ~ÓÇ B ˛õÓ˚flõˆÏÓ˚Ó˚ §yˆÏÌ ~ܲ!ê˛ fiê˛˛õܲܲ myÓ˚y Î%=˛– ≤ÃÙyî ã˛y˛õ G ï˛y˛õÙyeyÎ˚ ~ܲ!ê˛
àƒy§ AÈüÈˆï˛ Ó˚ˆÏÎ˚ˆÏSÈ– B §¡õ)î≈˲yˆÏÓ áy!°– §¡õ)î≈ §ÇfiÌy!ê˛ ï˛y˛õ#Î˚˲yˆÏÓ xhs˝!Ó˚ï˛ ÌyˆÏܲ– ~ál fiê˛˛õܲܲ!ê˛ ã˛y°% ܲÓ˚y
•ˆÏ°y– !l¡¨!°!áï˛ ≤ß¿à%!°Ó˚ í˛z_Ó˚ òyG /
ܲä A ~ÓÇ B ˆï˛ xÓ!fiÌï˛ àƒyˆÏ§Ó˚ ã)˛í˛¸yhs˝ ã˛y˛õ Ü˛ï˛ •ˆÏÓ⁄
áä àƒy§!ê˛Ó˚ xy˲ƒhs˝Ó˚#î ¢!=˛Ó˚ ˛õ!Ó˚Óï≈˛l Ü˛ï˛ ⁄
àä àƒy§!ê˛Ó˚ ï˛y˛õÙyeyÓ˚ ˛õ!Ó˚Óï≈˛l Ü˛ï˛ •ˆÏÓ⁄
âä P-V-T ï˛ˆÏ° xÓfiÌylÓ˚ï˛ §ÇfiÌy!ê˛Ó˚ åã)˛í˛¸yhs˝ §yÙƒyÓfiÌy í˛z˛õ!fiÌï˛ •GÎ˚yÓ˚ ˛õ)ˆÏÓ≈ä xhs˝Ó≈ï˛#≈ xÓfiÌy ÌyܲˆÏÓ !ܲ⁄
26ä ò%!ê˛ ò,ì˛¸ xÓ°¡∫ˆÏlÓ˚ ÙyˆÏV˛ ê˛yl ܲˆÏÓ˚ Ó˚yáy ~ܲ!ê˛ ï˛yÓ˚ 45 Hz Ù%°§)ˆÏÓ˚Ó˚ ܲ¡õyˆÏAܲ ܲ!¡õï˛ •ˆÏFSÈ– ï˛yÓ˚!ê˛Ó˚ ˲Ó˚ 3.5
x 10–2 kg ~ÓÇ ~Ó˚ ˜Ó˚!áܲ ˲Ó˚ âlc 4.0 x 10kg m–1 – åܲä ï˛yÓ˚!ê˛ˆÏï˛ !ï˛Î≈ܲ ï˛Ó˚ˆÏAàÓ˚ o%!ï˛ Ü˛ï˛ •ˆÏÓ⁄ åáä ï˛yˆÏÓ˚Ó˚
ê˛yl ܲï˛⁄
27ä ~ܲ!ê˛ !fl±ÈüÈ~Ó˚ §yˆÏÌ Î%=˛ ~ܲ!ê˛ Ë˛Ó˚ â£Ï≈î•#l xl%Ë)˛!Ùܲ ï˛ˆÏ° w ˆÜ˛Ô!îܲ ˆÓˆÏà Ù%=˛Ë˛yˆÏÓ à!ï˛¢#°– ˲Ó˚!ê˛ˆÏܲ x
xÓfiÌyˆÏl ˆê˛ˆÏl !lˆÏÎ˚ t=0 §ÙˆÏÎ˚ v ˆÓˆÏà ˆÜ˛ˆÏwÓ˚ !òˆÏܲ ˆë˛ˆÏ° ˆòGÎ˚y •°– ~Ó˚ ˆòy°ˆÏlÓ˚ !ÓhflÏyÓ˚ˆÏܲ w, x ~ÓÇ v ~Ó˚
§yˆÏ˛õˆÏ«˛ !lî≈Î˚ ܲÓ˚–
D xÌÓy
~ܲ!ê˛ !fiÌÓ˚ !Ó®% ˆÌˆÏܲ l ˜òˆÏâ≈ƒÓ˚ §)ï˛yÓ˚ §y•yˆÏ΃ ≤ð!¡∫ï˛ m ˲ˆÏÓ˚Ó˚ ~ܲ!ê˛ Ó› !˛õu˛ˆÏܲ GÓ˚ §yÙƒyÓfiÌyl ˆÌˆÏܲ «%˛o ò)Ó˚c
x ˛õÎ≈hs˝ ˆê˛ˆÏl ˆSȈÏí˛¸ ˆòGÎ˚y •°– ~ˆÏ«˛ˆÏe Ó› !˛õˆÏu˛Ó˚ à!ï˛Ó˚ ≤ÃÜ,˛!ï˛ !lÓ˚)˛õî ܲÓ˚–

!Ó˲yàÈüÈà : ≤Ã!ï˛!ê˛ ≤Èϟ¿Ó˚ Ùyl 3 : 3 x 7 = 21
28ä ò%Û˛≤Ãyhs˝ ò,ì˛¸Ë˛yˆÏÓ xyê˛Ü˛yˆÏly ~ܲ!ê˛ ï˛yˆÏÓ˚Ó˚ !ï˛Î≈ܲ §Ó˚î
y ( x, t ) = 0.06sin ((2 / 3π .× ).cos(120π t ) ˆÎáyˆÏl x G y m ~ܲˆÏܲ ~ÓÇ t, s ~ܲˆÏܲ ≤Ãܲy!¢ï˛–
ï˛yÓ˚!ê˛Ó˚ ˜òâ≈ƒ 1.5 m ~ÓÇ ~Ó˚ ˲ÏÓ˚ 3.0 x 10–2kg–
ܲä xˆÏ˛õ«˛Ü˛!ê˛ ˆÜ˛yl‰ ï˛Ó˚AàˆÏܲ ≤Ãܲy¢Ü˛ˆÏÓ˚ ÈüÈ ã˛°ï˛Ó˚Aà ly fiÌyl%ï˛Ó˚Aà⁄

áä ˛õÓ˚flõÓ˚ !Ó˛õÓ˚#ï˛ !òˆÏܲ à!ï˛¢#° ò%!ê˛ ï˛Ó˚ˆÏAàÓ˚ í˛z˛õ!Ó˚˛õyï˛ˆÏlÓ˚ Ê˛ˆÏ° §,T˛ ï˛Ó˚AàÓ˚)ˆÏ˛õ ~ˆÏܲ Óƒyáƒy ܲÓ˚–
àä ï˛yÓ˚!ê˛Ó˚ ê˛yl !lî≈Î˚ ܲÓ˚ –
29ä àƒyˆÏ§Ó˚ àï˛#Î˚ ï˛_¥ ˆÌˆÏܲ àƒyˆÏ§Ó˚ ã˛yˆÏ˛õÓ˚ ôyÓ˚îy òyG– àƒyˆÏ§Ó˚ ï˛y˛õÙyeyÓ˚ àï˛#Î˚ Óƒyáƒy òyG–
30ä ܲä ï˛y˛õ ˛õ!Ó˚Óy!•ï˛yAܲ Óƒyáƒy ܲÓ˚– ï˛y˛õÙyeyÓ˚ l!ï˛ Ó°ˆÏï˛ Ü˛# ˆÓyV˛yÎ˚⁄
áä xyˆÏ˛õ!«˛Ü˛ ï˛y˛õôyÓ˚ܲc Ó°ˆÏï˛ Ü˛# ˆÓyV˛yÎ˚⁄
31ä 400 kg ˲ˆÏÓ˚Ó˚ ~ܲ!ê˛ Ü,˛!eÙ í˛z˛õ@˝Ã• 2R Óƒy§yˆÏô≈Ó˚ Ó,_yܲyÓ˚ ˛õˆÏÌ ˛õ,!ÌÓ#Ó˚ ã˛yÓ˚!òˆÏܲ â%Ó˚ˆÏSÈ– 4R Óƒy§yˆÏô≈Ó˚ ~ܲ!ê˛
Ó,_yܲyÓ˚ ˛õˆÏÌ í˛z˛õ@˝Ã•!ê˛ˆÏܲ í˛zߨ#ï˛ Ü˛Ó˚ˆÏï˛ Ü˛# ˛õ!Ó˚Ùyî ¢!=˛Ó˚ ≤ÈÏÎ˚yçl •ˆÏÓ⁄ ~ˆÏ«˛ˆÏe à!ï˛¢!=˛ G !fiÌ!ï˛¢!=˛Ó˚ ܲ#Ó˚)˛õ ˛
õ!Ó˚Óï˛≈l •ˆÏÓ⁄ (R •ˆÏ°y ˛õ,!ÌÓ#Ó˚ Óƒy§yô≈ä
D xÌÓy
¢!=˛Ó˚ §ÇÓ˚«˛î l#!ï˛Ó˚ §y•yˆÏ΃ ˛õ,!ÌÓ#˛õ,¤˛ ˆÌˆÏܲ Ù%!=˛o%!ï˛ !lÓ˚)˛õî ܲÓ˚– §)Î≈ ~ÓÇ xlƒylƒ @˝ÃˆÏ•Ó˚ í˛z˛õ!fiÌ!ï˛Ó˚ ≤Ã˲yÓ
í˛zˆÏ˛õ«˛y ܲÓ˚ˆÏ°ñ ~•z Ù%=˛o%!ï˛Ó˚ !ï˛là%î o%!ï˛ˆÏï˛ ˆÜ˛yˆÏly Ó›ˆÏܲ í˛zˆÏô≈ !lˆÏ«˛˛õ ܲÓ˚ˆÏ° ˛õ,!ÌÓ# ˆÌˆÏܲ ΈÏÌT˛ ò)Ó˚ˆÏc ˙ Ó›Ó˚
o%!ï˛ Ü˛ï˛ •ˆÏÓ⁄
32ä 15 kg ˲ˆÏÓ˚Ó˚ ~ܲ!ê˛ ÓœÜ˛ˆÏܲ ~ܲ!ê˛ °¡∫y ê˛∆!°Ó˚ í˛z˛õÓ˚ Ó§yˆÏly xyˆÏSÈ– ÓœÜ˛ G ê˛∆!°Ó˚ ÙˆÏôƒ !fiÌï˛ÈüÈâ£Ï≈îà%îyAܲ •ˆÏ°y 0.18–
ê˛∆!°!ê˛ !fiÌÓ˚ xÓfiÌy ˆÌˆÏܲ 0.5 ms–2 cÓ˚ˆÏî 20s ã˛°yÓ˚ ˛õÓ˚ §Ùà!ï˛ˆÏï˛ ã˛°ˆÏï˛ °yàˆÏ°y– !l¡¨!°!áï˛ ˆ«˛eà%!°ˆÏï˛ ò¢≈ˆÏܲÓ˚
ܲyˆÏSÈ Ó›!ê˛Ó˚ à!ï˛ Ü˛# ÙˆÏl •ˆÏÓ Óƒyáƒy ܲÓ˚ /
ܲä Ùy!ê˛ˆÏï˛ òÑy!í˛¸ˆÏÎ˚ Ìyܲy ò¢≈ˆÏܲÓ˚ ܲyˆÏSÈ–
áä ê˛∆!°Ó˚ §yˆÏÌ ã˛°Ùyl ò¢≈ˆÏܲÓ˚ ܲyˆÏSÈ–
33ä ~ܲ!ê˛ Ü˛îy t = 0s §ÙˆÏÎ˚ Ù)°!Ó®% ˆÌˆÏܲ 10.0 ɵjm / s ˆÓˆÏà ~ÓÇ (8.0ɵi + 2.0 ɵj ) ms −2 !fiÌÓ˚ cÓ˚ˆÏî x - y ï˛ˆÏ°
à!ï˛¢#° •ˆÏ°y– åÜ˛ä ˆÜ˛yl‰ §ÙˆÏÎ˚ ܲîy!ê˛Ó˚ x-fiÌylyAܲ 16m •ˆÏÓ⁄ ˙ §ÙˆÏÎ˚ ܲîy!ê˛Ó˚ y- fiÌylyAܲ Ü˛ï˛ •ˆÏÓ⁄ åáä ˙
§ÙˆÏÎ˚ ܲîy!ê˛Ó˚ o%!ï˛ÈüÈ•z Óy Ü˛ï˛ •ˆÏÓ⁄
34ä ôÓ˚y •ˆÏ°y ˆÎñ ~ܲ!ê˛ ê˛yl ܲÓ˚y ï˛yˆÏÓ˚Ó˚ ܲ¡õyAܲ (n) !l¡¨!°!áï˛ !Ó£ÏÎ˚à%!°Ó˚ í˛z˛õÓ˚ !lË≈˛Ó˚ ܲˆÏÓ˚ ı
ܲä ï˛yˆÏÓ˚Ó˚ ˜òâ≈ƒñ åáä ï˛yˆÏÓ˚Ó˚ í˛z˛õÓ˚ ≤ÃÎ%=˛ ê˛yl ~ÓÇ åàä ï˛yˆÏÓ˚Ó˚ ≤Ã!ï˛ ~ܲܲ ˜òˆÏâ≈ƒÓ˚ ˲Ó˚– Ùye#Î˚ §Aà!ï˛ ˛õÂô!ï˛Ó˚ §y•yˆÏ΃
n- ~Ó˚ §¡õÜ≈˛!ê˛ !lÓ˚)˛õî ܲÓ˚– åˆòGÎ˚y xyˆÏSÈ ˆÎñ k=1/2)–
D xÌÓy
~ܲ!ê˛ ˆ§y!í˛Î˚yÙ ˛õÓ˚Ùyî%Ó˚ xyܲyÓ˚ 2.5 A ï˛yÓ˚ àí˛¸ ˲Ó˚ âlc !lî≈Î˚ ܲÓ˚– 刧y!í˛Î˚yˆÏÙÓ˚ ˛õyÓ˚Ùyî!Óܲ ˲Ó˚ 23g ~ÓÇ
0

xƒyˆÏ˲yàyˆÏí»˛yÓ˚ §ÇáƒyÓ˚ Ùyl 6.023 x 1023ä– !lî#≈ï˛ ~•z ÙyˆÏlÓ˚ §yˆÏÌ ˆÜ˛°y!§ï˛ ò¢yÎ˚ ˆ§y!í˛Î˚yˆÏÙÓ˚ âlc (970kg m–3)
ï%˛°ly ܲÓ˚– ~•z ò%•z âlˆÏcÓ˚ ÙyˆÏlÓ˚ Ü˛Ù !ܲ §Ùyl •Î˚⁄ Î!ò í˛z_Ó˚ •Ñƒy •Î˚ ï˛ˆÏÓ ˆÜ˛l ï˛y Óƒyáƒy ܲÓ˚–
!Ó˲yà ÈüÈ â / ≤Ã!ï˛!ê˛ ≤Èϟ¿Ó˚ Ùyl 5 / 5 x 3 = 15
35ä åܲä ~ܲ•z !Ó®%ˆÏï˛ !ܲÎ˚y¢#° ò%!ê˛ §Ùçyï˛#Î˚ ˆË˛QˆÏÓ˚Ó˚ °kô ˆË˛QˆÏÓ˚Ó˚ Ùyl !lî≈Î˚ ܲÓ˚– 3+2
áä (ɵi + ɵj ) x!˲Ù%ˆÏá A = 2iɵ + 3 ɵj ˆË˛QÓ˚!ê˛Ó˚ í˛z˛õyÇ¢ !lî≈Î˚ ܲÓ˚–
xÌÓy
Ü˛ä §ÙcÓ˚ˆÏî à!ï˛¢#° ˆÜ˛yˆÏly ܲîyÓ˚ n-ï˛Ù §ÙÎ˚ÈüÈxÓܲyˆÏ¢ ܲîy!ê˛Ó˚ §Ó˚î
Sn = u + (1/2)a (2n–1) ˆÎáyˆÏl !ã˛•´à%!° ≤Ãã˛!°ï˛ xˆÏÌ≈ ÓƒÓ•,ï˛–
áä ~ܲ!ê˛ Ü˛îyÓ˚ xÓfiÌyl !l¡¨!°!áï˛ §Ù#ܲÓ˚ˆÏîÓ˚ §y•yˆÏ΃ ≤Ãܲy¢ ܲÓ˚y ÎyÎ˚ ı
r = 3.0tiɵ + 4.0t ɵj + 5.0kɵ ˆÎáyˆÏl r-ˆÜ˛ m ~ܲˆÏܲ ~ÓÇ tÈüÈˆÜ˛ s ~ܲˆÏܲ ˆlGÎ˚y •ˆÏÎ˚ˆÏSÈ– t = 1.0s §ÙˆÏÎ˚ ~•z ܲîy!ê˛Ó˚
ˆÓà G cÓ˚î !lî≈Î˚ ܲÓ˚–
36ä åܲä xˆÏ«˛Ó˚ §yˆÏ˛õˆÏ«˛ â)î≈yÎ˚Ùyl Ó›Ó˚ ê˛Ü≈˛ G ˆÜ˛Ô!îܲ cÓ˚ˆÏîÓ˚ Ó˚y!¢Ùy°y !lî≈Î˚ ܲÓ˚–
åáä ˆòáyG ˆÎ xˆÏ«˛Ó˚ §yˆÏ˛õˆÏ«˛ â)î≈yÎ˚Ùyl ˆÜ˛yˆÏly Ó›Ó˚ ˆÜ˛Ô!îܲ ˲Ó˚ˆÏÓˆÏàÓ˚ ˛õ!Ó˚Óï≈˛ˆÏlÓ˚ •yÓ˚ ï˛yÓ˚ í˛z˛õÓ˚ ˛≤ÃÎ%=˛ ê˛ˆÏÜ≈˛Ó˚ ܲÙyl–
xÌÓy

ܲä xˆÏ«˛Ó˚ §yˆÏ˛õˆÏ«˛ â)î≈yÎ˚Ùyl Ó›Ó˚ xyÓï≈˛ à!ï˛¢!=˛Ó˚ Ó˚y!¢Ùy°y !lî≈Î˚ ܲÓ˚–
áä Ó›Ó˚ ˲Ó˚ˆÏÓˆÏàÓ˚ §yˆÏÌ ~Ó˚ à!ï˛¢!=˛Ó˚ ˛õ!Ó˚Óï≈˛l ܲ#˲yˆÏÓ •Î˚ ï˛y ~ܲ!ê˛ ˆ°á!ã˛ˆÏeÓ˚ §y•yˆÏ΃ ˆòáyG–
37ä ôyÓ˚yˆÏÓ˚á ≤ÃÓyˆÏ•Ó˚ ˆ«˛ˆÏe ôyÓ˚yÓy!•Ü˛ï˛yÓ˚ §Ù#ܲÓ˚î!ê˛ Óƒyáƒy ܲÓ˚– xï˛ı˛õÓ˚ ÓyˆÏl≈y!°Ó˚ §Ù#ܲÓ˚î !lÓ˚)˛õî ܲÓ˚– ~Ó˚ §y•yˆÏ΃
ê˛!Ó˚ˆÏ§!°Ó˚ §)e!ê˛ !ÓÓ,ï˛ Ü˛Ó˚–
xÌÓy
ܲä ~ܲ!ê˛ §yw ÙyôƒˆÏÙ ˆÜ˛yˆÏly ˆày°#Î˚ Ó›Ó˚ ≤Ãy!hs˝Ü˛ ˆÓˆÏàÓ˚ Ó˚y!¢Ùy°y!ê˛ !lÓ˚)˛õî ܲÓ˚–
áä ~ܲ!ê˛ ˜Ü˛!¢Ü˛ lˆÏ° ï˛Ó˚ˆÏ°Ó˚ ˜Ü˛!¢Ü˛ í˛zayˆÏlÓ˚ Ó˚y!¢Ùy°y!ê˛ !lî≈Î˚ ܲÓ˚–

D x!ï˛!Ó˚=˛ ≤ß¿yÓ°#

Model Question
Class - XI : Physics : 70 Marks : 2020-2021

Section- A : Each question carries 1 mark : 1x20=20

1. In the euqation y = A sin (wt = kx)m, where x is in m and in ‘s’. Write the dimensional formula of ‘w’
and k.
2. Plot velocity time graph for a body thrown verticaly upward and returned back to the point of
projection.
OR
A body is projected horizontally from the top of a building. Draw velocity time graph for its horizontal
and vertical component of velocity.
3. A target can be hit at a known distance by hitting the shells at an angle of 600. For what other angle
the same can be hit ?
4. If the acceleration of a moving body varies with time, what does the area of acceration time graph for
any time internal represent.

5. If A = ɵi + 2 ɵj + 2kɵ and B = ɵi − ɵj + nkɵ are perperaticular to each other then find the value of ‘n’.
6. What is the relation between angle of repose and angle of firction ?
7. What is the apparent weight of a body of mass ‘m’ at the highest point it is just ‘looping the loop’ in
a vertical circle?
8. A lighter body and a heavier body moving with same kinetic energy are brought to rest by applying
same forces on them. Which one will come to rest at a shorter distance ?
9. What is the physical significance of moment of inestia ?
OR
What is babbating ?
10. Two idential cylinder starts from rest at the top of the inchined plane. One slides without rolling and
the other rolls with out slipping. Assuming that no mechanical energy dissipated as heat, which one of
them will reach the bottom of inclined planes earlier.
11. If the change in the value of ‘g’ at a height ‘h’ above the surface of the earth is the same as at a deph
d, (h<<R) R the radius of earch find the relation between d and h.

A
12. The stress strain graph for two materials
B
A and B are as shown in fig. Which of two
material is stronger ?

13. Water flows at a speed of 6 cm S–1 through a tube of radius 1 cm. coefficient of viscosity of water
at room temperature is 0.01 poise. Characterize the flow.
14. A beaker is filled upto the brin with water at 40C. Water overflows when beaker is either heated or
cooled, why ?

15. State 1st law of thermodynamics.
16. Introduce temparature on the basis of Zeroth law of thermodynamics.
17. What is critical temperature ?
18. Find the displacement when kinetic energy is half its maximum value in S.H.M.
19. Why does the shape of a pulse get distorted during propagation in a dispersive medium.
20. Two sitar strings A and B playing the note ‘Dha’ are slightly out of tune and produce beats of
frequency 5Hz. The tension in the string B is slightly increased and the beat frequency is found to
decrease by 3Hz. What is the original frequency of ‘B’ if frequency of A is 427 Hz?
Section -B : Each Question carries 2 marks : 2x7=14
21. ‘A freely falling body has zero weight’ – Explain.
3
22. A body of mass 0.5 kg travels in a straight line with velocity V= α . × 2 , where α = 5m −1s −1 What is
the work done by the net force during its displacement from x=0 to x=2m.
* OR
A bolt of mass 0.3 kg falls from the ceiling of an elevator moveing down with a uniform speed of 7ms1.
It hits the floor of the elevator (length of the elevator = 3m) and does not rebound. What is the heat
produced by the impact ? would your answer be different if the elevator were stationary ?
23. A perfectly elastic oblique collision takes place between two indentical bodies, one of which initially
was at rest. Show that after collision they move at right angles to each other.
24. Define gravitational field intensity. Write its unit and dimension.
25. Two cylinders A and B of equal capacity are connected to each other via a stop cock. ‘A’ contains
a gas at standard temperature and pressure and ‘B’ is completely evacuated. The entire system is
thermally insulated. The stopcock is suddenly opened. (i) What is the final pressure of gas in A and B.
b) What is the change in internal energy ?
(c) What is the change in temperature of the gas ?
(d) Do the intermediate state of the system (before setting to the final equilibrium state) lie on its P-V-
T surface ?
26. A wire stretched between two rigid supports vibrates in its fundamental mode with a frequency of
45 Hz. The mass of the wire is 3.5 x 10–2 kg and its linear density 4.0 x 10–2 kg/m what is (a) the speed
of transverse wave on the string and (b) the tension in the string.
27. A mass attached to a spring is free to oscillate with angular velocity w, in a horizontal plane without
friction or damping. It is pulled to a distance x0 and pushed towards the centre with velocity vo at time
t=0. Determine the amplitude of oscillations in terms of the parameters w, xo and vo.
* OR
A bob of mass ‘m’ is suspended from a fixed point with a thread of length ‘l’ . The bob in displaced from
its equilibrium position by a small distance x. Determine the nature of the motion of the bob.
Section -C : Each question Carried 3 Marks : 3x7=21
28. The transverse displacement of a string (claped at its two ends ) is given by
y ( x, t ) = 0.06sin ((2 / 3π .× ).cos(120π t ) , where x and y are in ‘m’ and t is in ‘s’. The length of the
string is 1.5m and its mass is 3.0 x10–2Kg.

(a) Does the function represent a travelling wave or a stationary wave ?
(b) Interpret the wave as a superposition of two waves travelling in opposite directions. What are
the wave length, frequency and speed of each wave ?
(c) Determine the tension in the string.
29. State the Concept of pressure exerted by a gas on the basis of kinetic theory. Give kinetic interpretation
of temperature.
30. (a) Explain ‘thermal conductivity’. What is meant by ‘Temperature Gradient’?
(b) What is meant by ‘Specific heat capacity’?
31. A 400 kg satellite is in a circular orbit of radius 2R about the earth (R be the radius of earth). How
much energy is required to transfer it to a circular orbit of radius 4R ? What are the changes in the
kinetic and potential energies ?
* OR
Based on the principle of conservationof energy, obtain escape speed on the surface of earth. If a body
is projected thrice this speed, what would be the speed of the body far away of earth (Ignore the
presence of sun and other planets)
32. A block of mass 15 kg is placed on a long trolley. The co-efficient of static friction between the
block and the trolley is 0.18. The trolley accelerates from rest with 0.5 m/s2 for 20s and then moves with
uniform velocity. Discuss the motion of the block as viewed by -
(a) a stationay observer on the ground.
(b) an observer moving with the trolley.

33. A particle starts from the origin at t=0 s with a velocity of 10.0 ɵjm / s and moves in the x-y plane
with a constant acceleration of (8.0ɵi + 2.0 ɵj ) ms −2
(a) at what time is the x co-ordinate of the particle is 16 m? What is the y co-ordinate at that time?
(b) What is the speed of the particle at that time?
34. Assuming that the frequency (v) of an stretched string depends on (i) Length of the string, (ii)
Tension acting along the string, (iii) mass per unit length of the string. Obtain a relation for (v) by the
method of dimension. (K=1/2).
* OR
Estimate the average mass density of a sodium atom of its size 2.5A (N=6.023x1023 and atomic mass
of sodium as 23g). compare it with the density of sodium in its crystalline phase, 970kg/m-3. Are the two
densities of the same order of magnitude ? If so why ?
Section - D : Each question carried 5 marks : 5x3=15
35. (a) Find out the resultant vector of two like vectors acting at a point.

(b) Find the component of A = 2iɵ + 3 ɵj along direction of (ɵi + ɵj ) (3+2)
OR
(a) Displacement in nth time during uniformly accelerated motion is Sn= u + 1/2a(2n–1), where symbols
have their usual meanings. Derive the relation graphically.

(b) The position of a particle is given by r = 3.0tiɵ + 4.0t ɵj + 5.0kɵ where ‘t’ is in s and r is in m.
Find its velocity and acceleration at t=1.0s 3+2

36. (a) Establish the relation between torque and angular acceleration of an object moving about an
axis.
(b)Show that the rate of change of angular momentum of an object rotating about an axis is equal to the
torque acting on it.
OR
(a) Find out the expression of rotational kinetic energy of a partice about an axis.
(b) Show the variation of kinetic energy of a body with momentum graphically. A lighter body and a
heavier body have same momentum. Which one has greater kinetic energy?
37. Explain equation of continuity in a stream line flow. Hence obtain Bernoullis equation. Apply it to
state Torricelli’s law.
OR
(a) obtain expression for terminal velocity of a spherical body in a viscous medium.
(b) Find expression for capillary by rise in a capillary tube (ascent formula) . 2+3