12th Science Maharashtra Board
In this category students supposed to ask questions which belong to std 12th maharashtra board Science
- A parallel plate capacitor has circular plates of radius 8 cm and plate separation 1mm. (A) 1.78 × 10⁻⁸ C 2
- If the difference between the radii of the two spheres of a spherical capacitor is increased The capacitance of a spherical capacitor is C = 4πε₀ (a b/b-a) where a and b are the radii of the concentric inner and outer conducting shel... 1
- A metal plate is introduced between the plates of a charged parallel plate capacitor. Suppose the parallel-plate capacitor has capacitance C₀, plates of area A and separation d. Assume the metal sheet introduced has the same a... 1
- The safest way to protect yourself from lightening is to be inside a car. Justify. There is danger of lightning strikes during a thunderstorm. Because trees are taller than people and therefore closer to the clouds above, t... 1
- A capacitor has some dielectric between its plates and the capacitor is connected to a DC source. Assume a parallel-plate capacitor, of plate area A and plate separation d is filled with a dielectric of relative permittivity (dielectric c... 1
- Two charges of magnitudes -4Q and +2Q are located at points (2a, 0) and (5a, 0) respectively. The sphere of radius 4a encloses only the negative charge Q₁ = -4Q. The positive charge Q₂ = +2Q being located at a distance of 5a from the... 1
- A 6 µF capacitor is charged by a 300 V supply. It is then disconnected from the supply and is connected Data: C = 6 µF = 6 × 10⁻⁶ F = C₁, V = 300 V C₂ = 3 µF The electrostatic energy in the capacitor = 1/2 Cv² = 1/2 (6 × 10⁻⁶)(300)² = 3 × 10⁻⁶... 1
- One hundred twenty five small liquid drops, each carrying a charge of 0.5 µC and each of diameter 0.1 m form a bigger Data : n = 125, q = 0.5 × 10⁻⁶ C, d = 0.1 m The radius of each small drop, r = d/2 = 0.05 m The volume of the larger drop being equal to the... 1
- The dipole moment of a water molecule is 6.3 × 10-30 Cm. A sample of water contains 1021 molecules Data: p = 6.3 × 10⁻³⁰ C∙m, N = 10²¹ molecules, E = 2.5 × 10⁵ N/C, θ₀ = θ₁ = 0°, θ = θ₂ = 90° W = pE(cos θ₀ – cos θ) The total work required... 1
- In a parallel plate capacitor with air between the plates, each plate has an area of 6 × 10-3 m2 and the separation Data: k = 1(air), A = 6 × 10⁻³ m², d = 2 mm = 2 × 10⁻³ m,V = 100V, t = 2 mm = d, k₁ = 6, ε₀ = 8.85 × 10⁻¹² F/m (i) The capacitance of the ai... 1
- What is gravitational Potential ? We measure the gravitational potential energy U of a body (1) by assigning U = 0 for a reference configuration (such as the body at a refere... 1
- Due to a single charge at a distance r, Force (F ) α 1/r2, Electric field (E ) α 1/r2 but Potential (V) α 1/ r. At a point a distance r from an isolated point charge, the force F on a point charge and the electric field E both vary as 1/r2, while the p... 1
- Is electrostatic potential necessarily zero at a point where electric field strength is zero? Justify. Electric potential is a scalar quantity while electric field intensity is a vector quantity. When we add potentials at a point due two or mo... 1
- If we apply a large enough electric field, we can ionize the atoms and create a condition In a sufficiently strong electric field, the molecules of a dielectric material become ionized, allowing flow of charge. The insulating prop... 1
- Series combination is used when a high voltage is to be divided on several capacitors. Capacitor with minimum capacitanc Series combination of capacitors Equivalent capacitance is less than the smallest capacitance in series. For several capacitors of given cap... 1
- A 0.1 m solution of K2SO4 in water has a freezing point of – 4.3 °C. Given: Molality of K₂SO₄ solution = m = 0.1 m Freezing point of solution = T_f = – 4.3 °C K_f of water = 1.86 K kg mol^(–1)To find: van’t Ho... 1
- Write the equation relating boiling point elevation to the concentration of the solution. The boiling point elevation is directly proportional to the molality of the solution. Thus, Δ Tb ∝ m ∴ Δ Tb ∝ Kb m where, m is the molality... 1
- The distance between two consecutive bright fringes in a biprism experiment using light of wavelength 6000 Å Given : λ₁ = 6000 Å = 6 x 10⁻⁷ m, λ_(2 )= 4800 Å = 4.8 x 10⁻⁷ m, W₁ = 0.32 mm =3.2 x 10⁻⁴ m Distance between consecutive bright fringes, W =... 1
- A star is emitting light at the wavelength of 5000 Å. Determine the limit of resolution of a telescope Given : λ = 5000 Å = 5 x 10⁻⁷ m, D = 200 x 2.54 cm = 5.08 m θ = 1.22λ/D = frac(1.22)(5×10⁻⁷)5.08 = 1.2×10⁻⁷ rad 1
- Monochromatic electromagnetic radiation from a distant source passes through a slit. Given : 2W = 6mm W = 3mm = 3 x 10⁻^(3 )m, y=2.5 m, (a) λ₁ = 500 nm = 5 x 10⁻^(7 )m (b) λ₂ = 50 μm = 5 x 10⁻^(5 )m (c) λ_(3 )= 0.500 nm = 5 x... 1
- What must be the ratio of the slit width to the wavelength for a single slit to have the first diffraction Given : θ = 45°, m = 1 a sin θ = mλ for (m = 1, 2, 3... minima) Here, m = 1 (First minimum) a sin 45° = (1) λ ∴ a/λ = 1/sin 45° = 1.414 This... 1
- A parallel beam of green light of wavelength 546 nm passes through a slit of width 0.4 mm. Given : λ = 546 nm = 546 x 10⁻⁹ m, a = 0.4 mm = 4 x 10⁻⁴ m, D = 40 cm = 40 x 10⁻² m, y_md = mλD/a ∴ y₁d = 1λD/a And 2y₁d = 2λD/a =(frac2×546... 1
- The intensity of the light coming from one of the slits in Young’s experiment is twice the intensity of the light coming Given : I₁:I₂ = 2:1 If E₁₀ and E₂₀ are the amplitudes of the interfering waves, the ratio of the maximum intensity to the minimum intensity... 1
- In Fraunhoffer diffraction by a narrow slit, a screen is placed at a distance of 2 m from the lens Given: D = 2 m, y₁d = 5 mm = 5 x 10⁻³ m, a = 0.2 mm = 0.2 x 10⁻³ m = 2 x 10⁻⁴ m y_md = mλD/a ∴ λ = fracy_1daD=frac5×10⁻³×0.2×10⁻³2 ∴ λ = 5 x... 1