Tiêu đề P1C7 Properties of Matter With Solve.pdf ✅

c`v‡_©i MvVwbK ag©  Engineering Practice Content 1 c`v‡_©i MvVwbK ag© Structural Properties of Matter mßg Aa ̈vq ACS Physics Department Gi g‡bvbxZ cÖkœmg~n 1| 6 m `xN© Ges 2 mm2 cÖ ̄’‡”Q‡`i †ÿÎdj wewkó GKwU Zv‡ii mvnv‡h ̈ 10 kg Gi GKwU e ̄‘ Szjv‡bv nq| hLb e ̄‘wU mwi‡q †bqv nq ZLb Zvi •`N© ̈ nq 5.9975 m| Zv‡ii Dcv`v‡bi Bqs Gi ̧YvsK †ei K‡iv| [Medium] mgvavb: Y = FL Al = mgL Al = 10 × 9.8 × 6 2 × 10–6 × 0.0025 cÖK...Z •`N© ̈, L = 5.9975 m fi †`Iqvi ci •`N© ̈ = L + l = 6m l = 6 – 5.9975 m = 0.0025 m = 1.176 × 1011 Nm–2 (Ans.) 2| B ̄úv‡Zi Bqs Gi ̧Yv1⁄4 2 × 1011 Nm–2 | 5 m `xN© 2 mm e ̈vmwewkó B ̄úv‡Zi Zv‡ii 2.5 cm •`N© ̈ e„w×i Rb ̈ KZ fi †Svjv‡Z n‡e? [Easy] mgvavb: Y = FL Al  Y = mgL r 2 l  m = Yr 2 l gL Y = 2 × 1011 Nm–1 L = 5 m r = d 2 = 2 2 = 1 mm l = 2.5 cm = 2 × 1011 ×  × 10–6 × 2.5 × 10–2 9.8 × 5 kg  m = 320.6 kg (Ans.) Tricks: cÖkœ eyS‡Z mgm ̈v n‡j Pj‡Ki gvb ̧‡jv Avjv`v K‡i wj‡L wb‡Z cvi| 3| 2 m `xN© SzjšÍ GKwU Zv‡ii wb‡Pi cÖv‡šÍ 8 kg Gi fi Szjv‡j •`N© ̈ 0.5 mm ev‡o| Zv‡ii Dcv`v‡bi Bqs Gi ̧YvsK 2 × 1011 Nm–2 n‡j Zv‡ii cÖ ̄’‡”Q‡`i †ÿÎdj wbY©q K‡iv| [Easy] mgvavb: Y = FL Al  A = mgL Yl = 8 × 9.8 × 2 2 × 1011 × 0.5 × 10–3 m 2 L = 2m Y = 2 × 1011 Nm–2 m = 8 kg F = mg l = 0.5 mm = 1.568 × 10–6 m 2 (Ans.) 4| 2 mm e ̈vmhy3 GKwU Zv‡ii 1 mm •`N© ̈ evov‡Z 10.21 kg fi †Svjv‡Z nq| ZviwUi •`N© ̈ †ei K‡iv| Y = 2 × 1011 Nm–2 | [Easy] mgvavb: Y = FL Al L = Yr 2 l mg = 2 × 1011 × 10–6 × 10–3 10.21 × 9.8 = 6.2764 m (Ans.) 5| †Kv‡bv Zv‡ii •`N© ̈ 3 m Ges fi 20 gm| 50 N Gi Uv‡b Gi •`N© ̈ 1 mm ev‡o| Zv‡ii NbZ¡ 7.5 × 103 kgm–3 n‡j Gi Dcv`v‡bi Bqs-Gi ̧YvsK KZ? [Medium] mgvavb: Y = FL Al = 50 × 3 8.89 × 10–7 × 10–3 Nm–2 = 1.69 × 1011 Nm–2 (Ans.) GLv‡b, A = V L = m L = 20 × 10–3 7.5 × 103 × 3 m 2 = 8.89 × 10–7 m 2 6| 1.8 m •`‡N© ̈i I 6 × 10–4 m e ̈v‡mi GKwU ÷x‡ji Zv‡ii GK cÖvšÍ N‡ii Qv‡`i GKwU û‡Ki mv‡_ †eu‡a Aci cÖv‡šÍ 8 kg fi Szwj‡q w`‡j ZviwU KZUzKz •`‡N© ̈ e„w× cv‡e? ÷x‡ji Bqs-Gi ̧YvsK 2.2 × 1011 Nm–2 [Easy] mgvavb: d = 6 × 10–4 m 8 kg Y = FL Al = mgL Al  l = mgL YA = 8 × 9.8 × 1.8  × 2.2 × 1011 × (3 × 10–4 ) 2 m = 2.27 × 10–3 m (Ans.) 7| GKwU avZe Nb‡Ki cÖwZwU Z‡ji †ÿÎdj 0.5 m2 Gi wbP Zj `„pfv‡e AvUK‡bv| DcwiZ‡j 5 × 106 N ̄úk©K ej cÖ‡qvM Ki‡j K...šÍb weK...wZ 10 nq| avZzwUi KvwV‡b ̈i ̧YvsK wbY©q K‡iv| [Easy] mgvavb: ̄úk©K ej  = 10 F A = 5 × 106 0.5 = 107 Nm–2  = 10 = 0.1745 rad n = K...šÍb cxob K...šÍb weK...wZ = 107 0.1745 = 5.73 × 107 Nm–2 8| GKwU DPz `vjv‡bi evB‡ii w`‡K B‡Ui Ici GKwU Kbμx‡Ui AveiY †`qv nq| Kbμx‡Ui AveiY B‡Ui †`qv‡ji Ici 0.01 m e ̈vmv‡a©i ÷x‡ji †ejybvKvi wc‡bi mvnv‡h ̈ jvMv‡bv n‡q‡Q| cÖwZwU Avjwcb‡K 1000 kg fi enb Ki‡Z n‡jÑ [Medium]
2  Physics 1st Paper Chapter-7 (i) Avjwc‡bi Ici e ̈eZ©b cxob KZ? mgvavb: e ̈eZ©b cxob = F A = mg r 2 = 1000 × 9.8  × (0.01) 2 = 3.12 × 107 Nm–2 (Ans.) (ii) Avjwc‡bi e ̈eZ©b weK...wZ KZ? ÷x‡ji e ̈eZ©b ̧YvsK 8.4 × 1010 Nm–2 mgvavb:  e ̈eZ©b weK...wZ = e ̈eZ©b cxob e ̈eZ©b ̧YvsK = 3.71 × 10–4 (Ans.) 9| GKwU avZe Nb‡Ki cÖwZ evûi •`N© ̈ 0.1; m Gi wbPZj `„pfv‡e AvUKv‡bv| DcwiZ‡j 5 × 106 N ̄úk©K ej cÖ‡qvM Kivq Nb‡Ki Dc‡ii c„ô wb‡Pi Z‡ji mv‡c‡ÿ 10–4 m m‡i hvq| e ̈eZ©b cxob, e ̈eZ©b weK...wZ I e ̈eZ©b ̧YvsK KZ? [Easy] mgvavb: 10 ̄úk©K ej –4 m e ̈eZ©b cxob = F A = 5 × 106 0.12 Nm–2 = 5 × 108 Nm–2 e ̈eZ©b weK...wZ =  h = 10–4 0.1 = 10–3  e ̈eZ©b ̧bvsK = e ̈eZ©b cxob e ̈eZ©b weK...wZ = 5 × 1011 Nm–2 10| 0.5 mm e ̈vmva© wewkó GK cÖKvi Zv‡ii weK...wZ 1 1000 A‡cÿv †ewk n‡j Gi ̄’vqx weK...wZ N‡U| Bqs-Gi ̧YvsK 20 × 1010 Nm–2 n‡j ̄’vqx weK...wZ m„wó bv K‡i H Zvi n‡Z m‡e©v”P KZ fvi †Svjv‡bv hv‡e? [Medium] mgvavb: Y = cxob weK...wZ  F A = Y × weK...wZ GLv‡b, weK...wZ = 1 1000  F = A × Y × weK...wZ  F = 20 × 1010 × 3.14 × (5 × 10–4 ) 2 1000 = 157 N 11| 5 × 107 Nm–2 Pv‡c 1000 cc cvi` KZUzKz msKzwPZ n‡e? cvi‡`i AvqZb ̧YvsK 2.5 × 1010 Nm–2 [Easy] mgvavb: P = 5 × 107 Nm–2 K = 2.5 × 1010 Nm–2 V = 1000 cc = 1000 × 10–6 m K = PV v  v = 5 × 107 × 1000 × 10–6 2.5 × 1010 Nm–2 m 3 = 2 × 10–6 m 3 = 2 cc (Ans.) 12| GKwU †Mvj‡Ki e ̈vmva© 10 cm| Gi Ici 50 evqygÛjxq Pvc cÖ‡qvM Kiv n‡j 0.1 cc K‡g †Mj| Gi AvqZb ̧YvsK KZ? [Easy] mgvavb: K = PV v = 50 × 101325 × 4 3 (.10) 3 1 × 10–7 Nm–2 = 2.12 × 1011 Nm–2 (Ans.) r = 10 cm v = 4 3 r 3 13| cvi‡`i AvqZb ̧YvsK 2.5 × 1010 Nm–2 GK wjUvi cvi‡`i Ici Kx cwigvY Pvc cÖ‡qvM Ki‡j AvqZb 2 × 10–6 m 3 n«vm cv‡e? [Easy] mgvavb: v = 2 × 10–6 m 3 = 2 cm3 K = 2.5 × 1010 Nm–2 V = 1L = 1000 cm3 K = PV v  P = Kv V = 2.5 × 1010 Nm–2 × 2 1000 Nm–2 = 5 × 107 Nm–2 (Ans.) 14| GKwU B ̄úv‡Zi Zv‡ii cÖ ̄’‡”Q‡`i †ÿÎdj 1 × 10–6 m 2 I Amn weK...wZ 4.9 × 10–3 | ZviwU‡Z •`N© ̈ eivei m‡e©v”P KZ ej cÖ‡qvM Kiv hv‡e? [B ̄úv‡Zi Bqs-Gi w ̄’wZ ̄’vcK ̧YvsK = 2 × 1011 Nm–2 ] [Easy] mgvavb: GLv‡b, F A = 4.9 × 10–3 × 2 × 1011  F = 980 N (Ans.) A = 1 × 10–6 m 2 l L = 4.9 × 10–3 Y = 2 × 1011 Nm–2 15| GKwU Zv‡ii Amn cxob 4.9 × 108 Nm–2 Ges cÖ ̄’‡”Q‡`i †ÿÎdj 1 × 10–6 m 2 n‡j Gi Amn IRb KZ? [Easy] mgvavb: F = Amn cxob × cÖ ̄’‡”Q‡`i †ÿÎdj = 4.9 × 108 × 10–6 N = 490 N (Ans.) P = F A P = 4.9 × 108 Nm–2 A = 10–6 m 2 16| cvi‡`i AvqZ‡bi w ̄’wZ ̄’vcK ̧YvsK 2.6 × 1010 Pa n‡j msbg ̈Zv wbY©q K‡iv| [Easy] mgvavb: msbg ̈Zv = 1 K K = 2.6 × 1010 Pa = 1 2.6 × 1010 = 3.846 × 10–11 Pa–1
c`v‡_©i MvVwbK ag©  Engineering Practice Content 3 17| 1 mm2 cÖ ̄’‡”Q`wewkó GKwU B ̄úv‡Zi Zv‡ii •`N© ̈ 5% e„w× Ki‡j KZ ejcÖ‡qvM Ki‡Z n‡e? [B ̄úv‡Zi Bqs Gi ̧YvsK Y = 2 × 1011 Nm–2 ] [iv. †ev. 10; w`. †ev. 10; e. †ev. 02; Xv. †ev. 06; wm. †ev. 11, 07; Kz. †ev. 11, 09] [Easy] mgvavb: Y = FL Al  F = YAl L = 2 × 1011 × 10–6 × L 20 L N = 104 N (Ans.) A = 1 mm2 = 10–6 m 2 l = L Gi 5% = L 20 Y = 2 × 1011 Nm–2 18| Kx cwigvY ej cÖ‡qvM Ki‡j 1.0 eM© †m.wg. cÖ ̄’‡”Q`wewkó †Kv‡bv B ̄úvZ Zvi Gi Avw` •`‡N© ̈i wØ ̧Y n‡e? [Y = 2 × 1011 Nm–2 ] [iv. †ev. 01; P. †ev. 04] [Easy] mgvavb:  F = YAl L = 2 × 1011 × 10–4 N = 2 × 107 N (Ans.) l = 2L – L = L A = 1 cm2 = 10–4 m 2 Y = 2 × 1011 Nm–2 19| 10 m j¤^v Ges 1 mm e ̈vmwewkó GKwU Zvi‡K 100 N ej Øviv Uvbv n‡jv| Zv‡ii •`N© ̈ KZUzKy e„w× cv‡e †ei K‡iv| [Y = 2 × 1011 Nm–2 ] [wm. †ev. 02; h. †ev. 10; iv. †ev. 02; w`. †ev. 11] [Easy] mgvavb: Y = FL Al  l = FL YA = 100 × 10 2 × 1011 ×  × (5 × 10–4 ) 2 m = 6.37 × 10–3 m (Ans.) r = 1mm 2 = 0.5 × 10–3 m L = 10 m F = 100 N 20| GKwU Zv‡ii Dcv`v‡bi Bqs-Gi MyYvsK 2 × 1011 Nm–2 , ZviwUi •`N© ̈ 15% e„w× Ki‡Z n‡j cÖhy3 cxob wbY©q K‡iv| [Kz. †ev. 02; e. †ev. 07] [Easy] mgvavb: Y = FL Al  F A = Yl L = 2 × 1011 × .15 = 3 × 1010 Nm–2 (Ans.) l = L Gi 15% = 0.15 L Y = 2 × 1011 Nm–2 P = F A = ? 21| 0.01 eM© †mw›UwgUvi cÖ ̄’‡”Q‡`i †ÿÎdj wewkó GKwU B ̄úv‡Zi Zv‡i 20 kg fi Szjv‡bv Ae ̄’vq Zv‡ii •`N© ̈ 6 m nq| fiwU AcmviY Ki‡j ZviwUi •`N© ̈ 5.995 m| B ̄úv‡Zi Bqs-Gi ̧YvsK KZ? [Medium] [wm. †ev. 06] mgvavb: Y = MgL Al = 20 × 9.8 × 5.995 0.01 × 10–4 × (6 – 5.995) Nm–2 = 2.35 × 1011 Nm–2 (Ans.) 22| GKwU avZe †Mvj‡Ki Ici 3 × 106 Nm–2 AvqZb cxob cÖ‡qvM Ki‡j 0.2 AvqZb weK...wZ nq| 4 × 106 Nm–2 AvqZ‡bi cxob cÖ‡qvM Ki‡j, AvqZb weK...wZ KZ n‡e? [iv. †ev. 08; e. †ev. 09] [Easy] mgvavb: GLv‡b, P1 v1 V = P2 v2 V = k  v2 V = 4 × 106 3 × 106 × 0.2 = 0.267 (Ans.) v1 V = 0.2 P = 3 × 106 Nm–2 23| 5.0 × 10–4 m e ̈vmwewkó GKwU Zv‡ii Dcv`v‡bi Bqs- Gi ̧YvsK 9.0 × 1010 Nm–2 | ZviwUi •`N© ̈ 5% e„w× Ki‡Z n‡j KZ ej cÖ‡qvM Ki‡Z n‡e? [P. †ev. 08] mgvavb: Y = 9 × 1010 Nm–2 d = 5 × 10–4 m Avw` •`N© ̈ = L l = 5 100 L  F = YAl L = 9 × 1010 × (2.5 × 10–4 ) 2 × 0.05 L L N = 883.6 N (Ans.) 24| GKwU B ̄úvZ Zv‡ii •`N© ̈ 2 m, cÖ ̄’‡”Q‡`i †ÿÎdj 1 eM©wg.wg.| ZviwUi cÖv‡šÍ 20 wbDUb ej cÖ‡qvM Ki‡j Gi •`N© ̈ e„w× wbY©q K‡iv| [Y = 2 × 1011 Nm–2 ] [Easy] mgvavb: Y = FL Al  l = FL AY = 20 × 2 10–6 × 2 × 1011 m l = 0.0002 m (Ans.) L = 2 m A = 1 mm2 = 10–6 m 2 F = 20 N Y = 2 × 1011 Nm–2 25| †Kv‡bv c`v‡_©i Amn cxob 4.9 × 108 Nm–2 | H c`v‡_©i •Zwi GKwU Zv‡ii cÖ ̄’‡”Q‡`i †ÿÎdj 1 mm2 n‡j ZviwU‡Z me©wb¤œ KZ fi Szjv‡bv n‡j Zv wQ‡o hv‡e? [Easy] mgvavb: GLv‡b, cxob = F A  4.9 × 108 = m × 9.8 10–6  m = 50 kg Amn cxob = 4.9 × 108 Nm–2 A = 1 mm2 = 10–6 m 2 Tricks: evg cv‡ki gZ †Póv Ki‡e Calculation K ̈vjKz‡jUi G Kivi| 26| wcZ‡ji GKwU Zv‡i 4.51 × 106 Nm–2 •`N© ̈ cxob cÖ‡qvM Kiv n‡j •`N© ̈ weK...wZ 5 × 10–5 nq| wcZ‡ji Bqs-Gi ̧YvsK wbY©q K‡iv| [Easy] mgvavb: Y = FL Al = 4.51 × 106 5 × 10–5 Nm–2 •`N© ̈ cxob = 4.51 × 106 Nm–2 •`N© ̈ weK...wZ = 5 × 10–5  Y = 9.02 × 1010 Nm–2 (Ans.)
4  Physics 1st Paper Chapter-7 27| 3 × 107 Nm–2 AvqZb cxo‡b †Kv‡bv c`v‡_©i AvqZb weK...wZ 1.5 × 10–4 n‡jv| H c`v‡_©i AvqZb ̧YvsK KZ? [Easy] mgvavb: AvqZb cxob, F A = 3 × 107 Nm–2 AvqZb weK...wZ, v V = 1.5 × 10–4 B = cxob weK...wZ = 3 × 107 1.5 × 10–4 Nm–2  B = 2 × 1011 Nm–2 (Ans.) 28| m‡e©v”P KZ •`‡N© ̈i GKwU B ̄úv‡Zi Zvi‡K †Kv‡bv `„p Aej¤^b †_‡K Szjv‡bv n‡j Zv wQo‡e bv? B ̄úv‡Zi NbZ¡ = 8 × 103 kgm–3 Ges Amn cxob = 9.8 × 108 Nm–2 | [Medium] mgvavb: GLv‡b, Amn cxob, F A = 9.8 × 108  mg A = ALg A = 9.8 × 108  L = 9.8 × 108  × g = 1.25 × 104 m (Ans.) 29| 10 m `xN© Ges 0.2 cm e ̈vm hy3 GKwU B ̄úv‡Zi Zv‡ii •`N© ̈ 2.5 cm e„w× Ki‡Z KZ e‡ji cÖ‡qvRb n‡e? B ̄úv‡Zi Bqs-Gi ̧YvsK = 2.1 × 1011 Nm–2 | [Easy] mgvavb: L = 10 m d = 0.2 cm = 0.2 × 10–2 m r = d 2 = 10–3 m l = 2.5 cm = 2.5 × 10–2 m Y = 2.1 × 1011 Nm–2  F = YAl L = 2.1 × 1011 × (0.1 × 10–2 ) 2 × 2.5 × 10–2 10 N = 1.65 × 103 N (Ans.) 30| 5 m `xN© Ges 1 × 10–6 m 2 cÖ ̄’‡”Q‡`i †ÿÎdj wewkó GKwU Abyf‚wgK B ̄úv‡Zi Zv‡ii Dfq cÖvšÍ‡K ci ̄úi wecixZ w`K †_‡K 20 wK‡jvMÖvg IR‡bi ej Øviv Uvb‡j Zv‡ii Dfq cÖv‡šÍi w`‡K Zv‡ii •`N© ̈ 25 × 10–4 m e„w× cvq| B ̄úv‡Zi Bqs-Gi ̧YvsK wbY©q K‡iv| [Medium] mgvavb: Y = FL Al = 20 × 9.8 × 5 10–6 × 2 × 25 × 10–4 Nm–2 = 1.96 × 1011 Nm–2 (Ans.) L = 5 m A = 10–6 m 2 F = 20 kgwt = 196 N l = 2×25×10–4 m 31| `ywU mgvb •`‡N© ̈i Zvi A I B Gi e ̈vm h_vμ‡g 1 mm I 4 mm| Dfq‡K mgvb e‡j Uvbv n‡j A Gi •`N© ̈ e„w× B Gi •`N© ̈ e„w×i 4 ̧Y| A I B Gi Bqs ̧YvsK Zzjbv K‡iv| [Medium] mgvavb: YA YB = ABlB AAlA = d 2 B × 1 d 2 A × 4 = 16 4 = 4  YA : YB = 4 : 1 GLv‡b, YA = FL AAlA YB = FL ABlB lA = 4lB  lB lA = 1 4 dA = 1 mm dB = 4 mm 32| GK evqygÛjxq Pv‡c †Kv‡bv e ̄‘i AvqZb 3500 cm3 Ges 25 evqygÛjxq Pv‡c 3499.915 cm3 | e ̄‘i Dcv`v‡bi AvqZb ̧YvsK wbY©q K‡iv| GK evqygÛjxq Pvc = 1.013 × 105 Pa| [Medium] mgvavb: P = 24 × 101325 Pa V = 3500 cm3 = 3500 × 10–6 m 3 = 3500 × 10–6 m 3 v = (3500 – 3499.915) cm3 cm3 × 10–6 m 3  B = PV v = 24 × 1.013 × 105 × 3500 × 10–6 0.085 × 10–6 Nm–2 = 1.00108 × 1011 Nm–2 (Ans.) 33| 0.3 m •`N© ̈ Ges 10–6 m 2 cÖ ̄’‡”Q`wewkó Zv‡ii gv_vq 10 kg fi mshy3 K‡i †Nviv‡bv n‡”Q| Zv‡ii avZzi Amn cxob 4.8 × 107 Nm–2 n‡j e ̈e ̄’vwU‡K m‡e©v”P KZ †K.wYK †e‡M Abyf‚wgK Z‡j †Nviv‡bv hv‡e? [Medium] mgvavb: F A = cxob  mv2 r A = 4.8 × 107   2 = 4.8 × 107 × 10–6 10 × 0.3   = 4 rad/s (Ans.) r = 0.3 m A = 10–6 m 2 m = 10 kg Amn cxob = 4.8 × 107 Nm–2 34| 0.4 cm e ̈vmwewkó GKwU Zv‡i 25 kg Gi GKwU e ̄‘ Szwj‡q †`qv n‡jv| Zv‡ii 1 m Gi •`N© ̈ e„w× †c‡q 1.02 m n‡jv| Zv‡ii weK...wZ, cxob I Bqs Gi ̧YvsK †ei K‡iv| [Easy] mgvavb: weK...wZ = l L = 0.02 1 = 0.02 cxob, F A = 25 × 9.8 (0.002) 2 = 1.95 × 107 Nm–2  Y = cxob weK...wZ = 9.75 × 108 Nm–2 r = d 2 = 0.004 2 m = 0.002 m L = 1m l = 0.02 m m = 25 kg W = mg
c`v‡_©i MvVwbK ag©  Engineering Practice Content 5 35| 3 m •`N© ̈i GKwU Zv‡ii cÖ ̄’‡”Q‡`i †ÿÎdj 4 mm2 | G‡Z 10 kg fvi Szjv‡bv n‡j (K) cxob (L) weK...wZ I (M) •`N© ̈ e„w× †ei K‡iv| (Y = 1.96 × 1011 Nm–2 ) mgvavb: (K) cxob = F A = mg A = 10 × 9.8 4 × 10–6 Nm–2 GLv‡b, L = 3m A = 4 × 10–6 m 2 m = 10 kg = 2.45 × 107 Nm–2 (Ans.) (L) weK...wZ = cxob Y = 2.45 × 107 1.96 × 1011 = 1.25 × 10–4 (M) weK...wZ = l L  l = weK...wZ × L = 1.25 × 10–4 × 3 = 3.75 × 10–4 m (Ans.) 36| GKwU Zv‡ii •`N© ̈ 3 m, e ̈vm 0.002 m, Amn cxob 6 × 107 Nm–2 | ZviwUi Amn IRb KZ? [Easy] mgvavb:Amn cxob = Amn ej †ÿÎdj F = A × Amn cxob = 3.14 × 0.0012 × 6 × 107 N = 188.5 N (Ans.) L = 3m d = 0.002m r = 0.001m Amn cxob = 6 × 107 Nm–2 37| evqyi AvqZb ̧YvsK 1.015 × 104 Nm–2 | †Kv‡bv wbw`©ó AvqZ‡bi evqy‡Z k~b ̈ AvqZ‡b wb‡q Avm‡Z Gi Ici Kx cwigvY Pvc cÖ‡qvM Ki‡Z n‡e? [Medium] mgvavb: K = F/A v/V K = 1.015 × 104 Nm–2 v = V – 0 = V  K = P v V  P = Kv v = 1.015 × 104 × v v = 1.015 × 104 Nm–2 (Ans.) 38| 2 mm2 cÖ ̄’‡”Q‡`i GKwU Zv‡ii mv‡_ 15 kg fi Szjv‡bv Av‡Q| fi Szjv‡bv ZviwUi •`N© ̈ 4 m| Zv‡ii Dcv`v‡bi Bqs‡qi ̧YvsK 1.3 × 1010 Nm–2 | fi mwi‡q wb‡j •`N© ̈ Kx cwigvY msKzwPZ n‡e? [Medium] mgvavb: awi, •`N© ̈ e„w× = l Avw` •`N© ̈ = (4 – l) m Y = mg(4 – l) Al A = 2 mm2 = 2 × 10–6 m 2 m = 15 kg Y = 1.3 × 1010 Nm–2  1.3 × 1010 = 15 × 9.8 (4 – l) 2 × 10–6 × l  l = 0.0225 m (Ans.) 39| 8 m `xN© Ges 1.5 × 103 kgm–3 Nb‡Z¡i GKwU fvix ivev‡ii iwki GK cÖvšÍ †Kv‡bv †`qv‡ji wmwjs n‡Z Szwj‡q †`qv n‡j iwki wbR ̄^ IR‡bi Kvi‡Y KZUzKz •`N© ̈ e„w× NU‡e? (ivev‡ii Bqs Gi ̧YvsK, Y = 5 × 108 Nm–2 ) [Medium] mgvavb: Y = FL Al = mgL Al = VgL Al L = 8 m  = 1.5 × 103 kg/m3 Y = 5 × 108 Nm–2  l = L 2 g Y = 1.88 × 10–3 m 40| F F    l  GKwU Nb‡Ki cÖwZ evûi •`N© ̈ 10 cm Ges Dci I wb‡Pi Z‡j F = 105 N gv‡bi `yB mgvšÍivj wKš‘ wecixZgyLx ̄úk©Kxq ej cÖ‡qvM Kivq Dc‡ii ZjwUi 0.5 cm miY N‡U (wPÎvbyhvqx)| hw` 20 cm evûwewkó Nb‡Ki GKB iKg ejØq cÖ‡qvM Kiv nZ, Z‡e mi‡Yi cwigvY wbY©q K‡iv| [Medium] mgvavb: e ̈eZ©b weK...wZ,  = x L = 5 × 10–2 ; A = 0.12 m 2 = 0.01 m2 e ̈eZ©b ̧YvsK,  = F A = 2 × 108 Nm–2 GLv‡b, L = 20 cm n‡j,  = F A = x L cÖhy3 ej, F = 105 N x = 105 × 0.2 (0.2) 2 × 2 × 08 = 0.0025 m = 0.25 cm (Ans.) 41| GKwU Zv‡ii cÖ ̄’‡”Q‡`i †ÿÎdj 10–6 m 2 Ges G‡Z 100 N ej cÖ‡qvM Ki‡j 0.1% •`N© ̈ e„w× N‡U| Zv‡ii Dcv`v‡bi Bqs-Gi ̧YvsK KZ? [Easy] mgvavb: Y = F/A l/L = 100 × L 10–6 × 0.001 × L = 1011 Nm–2 (Ans.) A = 10–6 m 2 F = 100 N l = 0.001 L 42| GKwU Szjv‡bv avZe Zv‡ii GKcÖv‡šÍ 103 N ej cÖ‡qvM Kivq ZviwUi 1 mm •`N© ̈ e„w× cvq| GKB c`v‡_©i mgvb •`‡N© ̈i I Pvi ̧Y e ̈v‡mi Zv‡ii mgvb cwigvY •`N© ̈ e„w×i Rb ̈ cÖ‡qvRbxq ej KZ n‡e? [Medium] mgvavb: F1L A1l1 = F2L A2l2  F2 = F1 × r2 2 r1 2 = 103 × 42 = 16 × 103 N (Ans.) F1 = 103 N l1 = 10– 3 m d2 = 4 d1 l2 = 10–3 m