Mehapatel

R = {(a, b) : a ≤ b3}(i) Since (a, a) ∉ R as a ≤ a3 is not always true[Take a = 1/3. then a ≤ a3 is not true]∴ R is not reflexive.(ii) Also (a, b) ∈ R ⇏ (b, a) ∈ R[Take a = 1, b = 4, ∴ 1 ≤ 43 but 4 ≰ (l)3 ]∴ R is not symmetric.(iii) Now (a, b) ∈ R, (b, c) ∈ R ⇏ (a, c) ∴ R[Take a = 100, b = 5, c = 3, ∴ 100 ≤ 53, 5 ≤ 33 but 100 ≥ 33] R is not symmetric.

We have, Mass of the metal, m = 0.20 kg = 200 gInitial temperature of the metal, T1 = 150°CFinal temperature of the metal, T2 = 40°CCalorimeter has water equivalent of mass, m’ = 0.025 kg = 25 gVolume of water, V = 150 cm3 Mass (M) of water at temperature T = 27°C is,                     150 × 1 = 150 g Fall in the temperature of the metal,          ΔT = T1 – T2                = 150 – 40              = 110°C Specific heat of water, Cw = 4.186 J/g/°K Specific heat of the metal = C Heat lost by the metal, θ = mCΔT                       … (i) Rise in the temperature of the water and the calorime

The elasticity of a material is affected by the following factors: 
(i) Effect of temperature: On heating, mostly the elasticity of materials decreases.
(ii) Effect of impurities: Depending upon the nature of impurity, the elasticity of materials may increase or decrease.
(iii) Annealing: Annealing decreases the elasticity of materials.
(iv) Hammering and rolling: This process increases the elasticity of materials. Note: Annealing is a heat process where a metal is heated to a specific temperature /colour and then allowed to cool slowly. This softens the metal which means it can be cut an

(2x + 5)2 - (2x - 5)2 = [(2x)2 + 2(2x)(5) + (5)2] - [(2x)2 - 2(2x)(5) + (5)2]                            = [4x2 + 20x + 25] - [4x2 - 20x + 25]                            = 4x2 + 20x + 25 - 4x2 + 20x - 25                            = (4x2 - 4x2 ) + (20x + 20x) + (25 - 25)                            = 0 + 40x + 0                            = 40x

कांजीहौस एक प्रकार से पशुओं की जेल थी। निम्नलिखित कारणों से पशुओं की हाजिरी ली जाती होगी-1. पशुओं की संख्या का ठीक - ठीक पता चलने के लिए।2. पशुओं की सेहत की जानकारी रखने।3. आवारा, उत्पात मचानेवाले पशुओं को अलग रखने।4. उनमें से कोई भाग या मर तो नहीं गया है।

Particle velocity is the velocity of particle of media at any instant as a progressive wave travels through media.Wave velocity is the velocity with which a progressive wave travels in media. Displacement of particle at any instant t is,                                        ...(1) ∴                       ...(2) and                       ...(3) From (2) and (3),                      But  is wave velocity. So, the relation between particle and wave velocity is given by,                         

Here,          Frequency of the plane EM wave, v = 2 × 1010HzAmplitude of electric field,  E0 = 48 Vm-1  Therefore, Wavelength of the wave, λ = cv =3 × 1082 × 1010m = 1.5 × 10-2m Amplitude of oscillating magnetic field,B0 = E0c = 483 × 108T = 1.6 × 10-7T Energy density in electric field,          μE = 12 ε0 E2Energy density in magnetic field,         μB = 12μ0B2 Using the relation, we have                  E = cB,  uE = 12 ε0 (cB)2     = c2 12 ε0 B2 But,           c = 1μ0 ε0 ∴ μE = 1μ0 ε012ε0B2 = 12μ0B2 = μB Hence, the average energy density of electric field equals the average energy density

Diameter = 4.2 cm  Radius (r) =    Volume =              Density = 8.9 g per cm3Mass of the ball = Volume x Density= 38.808 x 8.9 = 345.39 g (approx.).

Formula for calculating successive discounts:∴ Single equivalent discount for 10% and 20%     Single equivalent discount for 28% and 50%      

Due to lanthanide contraction, the size of M3+ ions (i.e. Lu3+, Eu3+, Yb3+ and Ce3+) decreases and thus, the basix strength of their hydroxides decreases.The order of size of given M3+ ions isCe3+ > Eu3+ > Yb3+ > Lu3+Therefore, the order of basic strength of hydroxides isCe(OH)3 > Eu(OH)3 > Yb(OH)3 > Lu(OH)3

Biot-savart law states that, the magnetic field induction dB at a point due to current element is                 dB = μo4π I dl sinθr2 where,I.dl is the current element,r is the distance of point from the current elemnt and,θ is the angle between dl ⇀and r⇀.Expression for magnetic field at the centre of a circular coil :Consider a circular coil of radius r with center O. Let, I be the current flowing in the circular coil. Assume, that the current coil is made of a large number of current elements each of length dl .current element = I.dl Now, as per Biot Savart law we have,             

There are no advantages of dieting. Science has proved that dieting causes many physical and mental problems. It causes a lot of problems and your physique can even become worse than before.Some of the pitfalls of dieting are:a. Hair loss: The most common side effect of dieting is that you start to lose your hair. Lack of required amount of proteins and fats results in hair loss.b. Depression: There are many other reasons for depression in life. Dieting is one among them. When your body is not able to handle loads of activities, you feel pressure in mind which causes stress. Stress worsens th

Using Gauss theorem,

(i) गर्मी के दिनों में शरीर की सतह से बहुत सारा पानी पसीने के रूप में त्वचा से उतसर्जित होता है। इससे मूत्र में पानी को कम करने की आवश्यकता होती है ताकि शरीर में पानी का संरक्षण हो सके।इसलिए, वृक्काणु के विभिन्न भाग; जैसे हैनले का लूप पानी को दोबारा से अवशोषित कर लेते हैं। इससे मूत्र की मात्रा कम हो जाती है।(ii) सर्दियों के दिनों में जब शरीर की सतह से पानी की हानि न्यूनतम हो जाती है, तब यदि हम अधिक पानी पिटे हैं तो रक्त का सही संगठन बनाए रखने के लिए इसके अधिक उत्सर्जन की आवश्यकता पड़ती है। रक्त से पानी को दोबारा अवशोषित नहीं किया जाता है, बल्कि इसे वृक्क से मूत्र के रूप में उत्सर्जित कर दिया ज

The Satyashodhak Samaj was an association that propagated caste equality. It was founded by Jyotirao Phule.

Solved Questions Answers and Assignments for STD 9 - Online GSEB Textbook solutions for STD 9 - ધોરણ 9 હીન્દી ગુજરાતી ગણિત યોગ, સ્વાસ્થ્ય અને શારીરિક શિક્ષણ વિજ્ઞાન્ સંસ્કૃત સામાજીક વિજ્ઞાન્ | ગુજરાત બોર્ડ

Work function of the metal, ɸ0 = 4.2 eV                                               = 4.2 x 1.6 x 10–19 J                                                = 6.72 x10–19 J Wavelength of incident radiation, λ = 330 nm Now, using the formula for energy of a photon, E = hcλ⇒       E = 6.62 × 10-34 × 3 × 108330 × 10-9        = 6.018 × 10-19J As energy of incident photon E

Metallic character increases down a group and decreases along a period as we move from left to right. Hence the order of increasing metallic character is P < Si < Be < Mg < Na.

The stability of lyophilic sols is a result of two factors, the presence of a charge and the solvation of colloidal particles. On the other hand, the stability of lyophobic sols is only because of the presence of a charge. Thus, the lyophilic sol is more stable than lyophobic sol due to the extensive solvation.