Maharashtra State Board
- Define athermanous substances and diathermanous substances Athermanous substances- Substances that don't allow transmission of heat radiation through them are called athermanous substances. i.e. a su... 1
- If the density of oxygen is 1.44 kg/m3 at a pressure of 105 N/m2, find the root mean square Given : ρ = 1.44 kg/m^(3 ), P=10⁵ N/m² ∴ The root mean square velocity of oxygen molecules v_rms =√(3P/ρ) = √(3×10⁵/1.44) m/s = 4.564 × 10^(... 1
- Write ideal gas equation for a mass of 7 g of nitrogen gas. In the usual notation, PV =nRT. n= Mass of the gas/Molar Mass =7/28= 1/4 Therefore, the corresponding ideal gas equation is PV = 1/4 RT. 1
- On what factors do the degrees of freedom depend? The degrees of freedom depends upon the structure of the molecule the temperature of the gas. the number of atoms forming a molecule 1
- What will happen to the mean square speed of the molecules of a gas if the temperature of the gas increases? If the temperature of a gas increases, the mean square speed of the molecules of the gas will increase in the same proportion. V^(2 )= 3nRT/... 1
- The ratio of emissive power of perfectly blackbody at 1327° C and 527 °C is (A) 4:1 (B) 16 : 1 (C) 2 : 1 (D) 8 : 1 (B) 16 : 1 The ratio of emissive power of perfectly blackbody at 1327° C and 527 °C is 16 : 1 1
- If a = 0.72 and r = 0.24, then the value of tr is (A) 0.02 (B) 0.04 (C) 0.4 (D) 0.2 (B) 0.04 tr=1-a-r =1-0.72-0.24 =0.04 2
- If pressure of an ideal gas is decreased by 10% isothermally, then its volume will (A) decrease by 9% (B) increase (D) increase by 11.11% 2
- The mean free path λ of molecules is given by C) 1/√(2)πnd² 1
- i) In an ideal gas, the molecules possess (A) only kinetic energy (B) both kinetic energy and potential energy (A) only kinetic energy 2
- Why is the surface tension of paints and lubricating oils kept low? Answer: so that paints and lubricating oils spread easily and wet the surface well. A liquid with high surface tension tends to pull itself... 1
- In Bernoulli’s theorem, which of the following is conserved? (A) linear momentum (B) angular momentum (C) mass (D) energy In Bernoulli’s theorem, Energy is conserved 2
- Two hail stones with radii in the ratio of 1:4 fall from a great height through the atmosphere. (C) 1:16 Two hail stones with radii in the ratio of 1:4 fall from a great height through the atmosphere. Then the ratio of their terminal ve... 1
- The energy stored in a soap bubble of diameter 6 cm and T = 0.04 N/m is nearly (A) 0.9 × 10-3 J (B) 0.4 × 10-3 J (A) 0.9 × 10⁻³ J The energy stored in a soap bubble of diameter 6 cm and T = 0.04 N/m is nearly 0.9 × 10⁻³ J 1
- Two capillary tubes of radii 0.3 cm and 0.6 cm are dipped in the same liquid. B) 2:1 Two capillary tubes of radii 0.3 cm and 0.6 cm are dipped in the same liquid. The ratio of heights through which the liquid will rise... 1
- A hydraulic lift is designed to lift heavy objects of maximum mass 2000 kg. The area of cross section of piston (A) 0.8711 × 10⁶ N/m^(2 ) 2
- Group and electronic configuration Answer: Elements in the same group of the modern periodic table have the same number of valence electrons, i.e. the same outermost electroni... 1
- Seg AM is a median of ∆ABC. If AB = 22, AC = 34, BC = 24, find AM. ∴ AM = 26 units 1
- Find the length of a diagonal of a rectangle having sides 11 cm and 60 cm. Answer: 61 cm A diagonal divides the rectangle into two right-angled triangles, with the sides of the rectangle as the legs and the diagonal... 1
- Do sides 7 cm, 24 cm, 25 cm form a right angled triangle? Give reason. The sides of the triangle are 7 cm, 24 cm and 25 cm. The longest side of the triangle is 25 cm. ∴ (25)² = 625 Now, sum of the squares of the... 1
- Find the height of an equilateral triangle having side 2a. Let ∆ABC be the given equilateral triangle. ∴ ∠B = 60° [Angle of an equilateral triangle] Let AD ⊥BC, B – D – C. In ∆ABD, ∠B = 60°, ∠ADB = 9... 1
- Explain tha disorders -Abinism Answer: Albinism is a hereditary (genetic) disorder in which the body cannot produce the pigment melanin, so the skin, hair and eyes lack no... 1
- Slim person feel more cold in winter the fat persons. Answer: Fat persons have a thicker layer of fat (adipose tissue) under the skin, which acts as an insulator and reduces heat loss. Slim pers... 1
- What precautions will you take during field visit Strictly obey instructions given by teachers. Ensure safety of oneself and others, carry first – aid box, identity cards, etc. for emergency... 1