#physics
- A common transistor radio set requires 12V (D.C.) for its operation. The D.C. source is constructed by using a transformer The correct answer is 440 N_pover N_s=V_pover V_s N_pover24=220over12 N_p=200×24over12 N_p=440 1
- An unpolarized light beam is incident on the polarizer of a polarization experiment and the intensity of light beam emerging The correct answer is 75 I₀cos²30°=100×(sqrt3over2)² =100×3over4 =75 1
- The coefficient of static friction between a wooden block of mass 0.5 kg and a vertical rough wall is 0.2. the correct answer is 25 N Given:: μ_s = 0.2 Solution:: m=0.5 kg g=10 m/s² We know that f_s= μ N To keep the block adhere to the wall here N... 1
- An audio signal υm = 20sin2π(1500t) amplitude modulates a carrier υc =80 sin 2π (100,000t). The value of percent modulation is ________. Correct answer is 25 v_m = 20 sin [100π t+πover4] :v_c = 80 sin [10⁴π t+πover6] we know that, modulation index = A_mover A_c from given equa... 1
- A resonance circuit having inductance and resistance 2 × 10–4 H and 6.28 Ω respectively oscillates at 10 MHz frequency. correct answer is 2000 R = 6.28 Ω f = 10 MHz L = 2 × 10⁻⁴ Henry We know that quality factor Q is given by ⇒ Q = X_L / R = ωL / R also, ω = 2... 1
- Each side of a box made of metal sheet in cubic shape is ‘a’ at room temperature ‘T’, the coefficient of linear expansion of the metal sheet is ‘α’. The correct Answer is C) 3a³αΔT ΔV = VγΔT ΔV = 3a³αΔT 2
- The focal length f is related to the radius of curvature r of the spherical convex mirror by: The correct Answer is B) f = +½ r Explaination : So, r / 2 = f f = +½ r 1
- A current through a wire depends on time as i = α0t + βt2 where α0 = 20 A/s and β = 8 As-2. Find the charge crossed through a section of the wire in 15 s. Correct Answer is B) 11250 C Explaination :: we have , i = α₀t + βt² , α = 20 A/s and β = 8As⁻² ,t = 15 sec We know that , i= dqover dt⇒ ∫₀^... 1
- Statement-I: Two photons having equal linear momenta have equal wavelengths. Statement-II: If the wavelength of a photon is decreased, Correct option is d) Statement-I is true but Statement-II is false Energy of photon E = hc / λ = E ∝ 1 / λ Hence, energy of photon increases... 1
- A block of mass m, lying on a smooth horizontal surface, is attached to a spring (of negligible mass) of spring constant k. the correct answer is option C) Fover√(mk) Detailed solution:: Maximum speed is at mean position (equilibrium). F = kx x=Fover k W_F + W_sp... 1
- The kinetic energy needed to project a body of mass m from the earth surface (radius R) to infinity is V_(e= √(2gR) _______ Formula of Escape velocity) _( ).^(.). Kinetic Energy = 1over2mv_e²= 1over2m×2gR mgR option C is correct 1
- What is the angular momentum of the electron in the third Bohr orbit in the hydrogen atom? Angular momentum of an electron in the nth Bohr orbit of hydrogen atom L= nh over 2π For n=3 L=3hover 2π L=3×1.055×10⁻³⁴ L=3.165 × 10⁻³⁴ Kg... 1
- The Boolean expression for an AND gate is ____. a) A+B b) A.B c) A+B d) A.B b) A.B is the correct answer 2
- A simple pendulum is suspended from the roof of a train. If the train is moving with an acceleration of 49 cm/s2 , pseudo force=ma gravity=mg tan θ = maover mg θ = tan⁻¹(maover mg) =tan⁻¹( 0.49over 9.8) =tan⁻¹(0.05) = 3 ^o 1
- A pulley of radius 2 m is rotated about its axis by a force F =20t-5t2 newton Torque is given by τ = FR Or α = FR/I Given F =20t – 5t2 R = 2m, I = 10 kgm2 α = (20t-5t²)×2over 10 α = 4t – t 2 ω=∫_t²α dt=2t²-t³/3 at ω =0... 1
- A particle undergoes uniform circular motion. About which point on the plane of the circle, The force will pass through the centre of the circle. Therefore, the angular momentum will remain conserved at the centre of the circle. hen... 1
- Two-point masses of 0.3kg and 0.7kg are fixed at the ends of a rod which is of length Work-energy theorem, W_allforces= 1over2 Iw² Given: w is constant So required work done to be minimum implies that I must be minimum. Let th... 1
- all physics formulas {maharashtra board} read below pdf for all formulas from modern physics and shortcut files deleted edit01** 1