All questions
- Rate of formation of SO3 in the following reaction 2SO2 + O2 → 2SO3 is 100 g min–1. The correct answer is D) 20 g/min Solution :: dover dt [SO₃]=100 g/min =100over80mole/min =1.25 mole/min -1over2dover dt[SO₂] [SO₃]=-dover d... 1
- Draw the energy band diagram when intrinsic semiconductor (Ge) is doped with impurity atoms of Antimony (Sb). Answer :diagram: 2
- A particle of mass m with an initial velocity collides perfectly elastically with a mass 3 m at rest. It moves with a velocity The correct answer is option d) v=uover sqrt 2 Explaination :: mui+0=mvj+3mv' v'=uover3i-vover3j 1over2mu²=1over2mv²+1over2(3m)Big(big(uover... 1
- A particle executes simple harmonic motion with an amplitude of 5 cm. When the particle is at 4 cm from the mean position, the magnitude of its velocity The correct option is answer a) 8π/3 EXplaination :: v= w√(A²-x²) --speed Acceleeation a= -ω ²x As |v|=|a| ω =3over4⇒T = 2πover ω = 8πover3 1
- The mass of a spaceship is 1000 kg. It is to be launched from the earth’s surface out into free space. The correct answer is option (a) 6.4 x 10^(10 )Joules Explaination :: The energy required is given by = GMmover R = gR² × mover R (∵ g = GMo... 1
- If the distance between the earth and the sun were half its present value, the number of days in a year would have been The correct answer is 129 days option b Explaination : BY keplers third law T² ∝ R³ therefore ( T₂over T₁)²=( R₂over R₁)³ T_(1 )= 365 days ,... 1
- If the current flowing in a coil is reduced to half of its original value, The Correct option is D) E₂ = 1over4 E_(1 ) Explaination Current is become half of the given value. E=1over2Li² i.e. E₂over E₁=(i₂over i₁)²=... 1
- An amplitude modulated waves is represented by expression vm = 5(1 + 0.6 cos6280t) sin(211 × 104t) volts Correct option according to NTA is 5over 2V , 8V Solution :: V_m=5(5(1+0.6 cos 6280t)sin(2π×10⁴t) V_m=(5+3 cos 6280t)sin(2π×10⁴t) V_max= 5+3... 1
- Evaluate int {root x^2 + a^2} dx solve this question This can be best answer possible https://youtu.be/BmCM98ymuiY This video belongs to ganit yogi if they want we can remove it from here . 2
- Find the value of A and B if int(sinx/sin(x-alpha))dx= Answer: (b) (A, B) = (cosα, sinα) Write x = (x-α) + α , so sin x = sin(x-α)cosα + cos(x-α)sinα. Dividing by sin(x-α) : sin x/sin(x-α) = cosα... 1
- If f(x) = ∫t(sinx - sint)dt for t ∈ [0, x] then (A) f'''(x) + f''(x) Answer: (C) f'''(x) + f'(x) = cos x - 2xsin x Write f(x) = sin x∫₀^x t dt - ∫₀^x tsin t dt = dfracx²2sin x - (sin x - xcos x) . Differentiat... 1
- evaluate int x-1/(x+1)^3 e^x dx {integration question } The correct answer is e^xover (x+1)²+c Explaination: 1
- l,m,n are the pth and rth term of G.P all positive then Correct option is 4) 0 Let x and y are first term and common ratio of GP respectively. first and second row are identical =0 1
- find the value of α for which A2 = B, is The correct answer is option d) no real value Explanation:: 1
- A ^−1 = 1/6(A^ 2 +cA+dI) where c, d ∈ R, then pair of values (c, d) are _________ Correct answer is -6,11 Explanation::: 1
- A time-dependent force F = 6t acts on a particle of mass 1 kg. If the particle starts from rest, the work done by the force during the first 1 sec. will be : The correct option is c) 4.5 J F= 6t, m = 1Kg, u =0 Now, F=ma =m(dv/dt)=1x(dv/dt) dv/dt = 6t ∫ ^v₀dv =∫¹₀6tdt v= 3(1²– 0) = 3m/s From work-e... 1
- At time t = 0s particle starts moving along the x-axis. If its kinetic energy increases uniformly with time ‘t’, The correct option is d) 1/√(t) Linear dependency with initial Kinetic Energy as zero is given as KE = kt, where k is the proportionality co... 1
- Two masses of 1 g and 4g are moving with equal kinetic energy. The ratio of the magnitudes of their momenta is The correct option is c)1:2 p=√(2Em) Where p denotes momentum, E denotes kinetic energy and mdenotes mass. p₁over p₂=√(m₁over m₂) p₁over p₂... 1
- A body of mass m=10−2 kg is moving in a medium and experiences a frictional force F=−kv2. Its initial speed is v0= 10 ms−1. (c) 10⁻⁴ kg m−1 is the correct answer Mass m = 10² Kg Initial velocity v₀= 10 ms⁻¹ Time t = 10 s Frictional Force F=− kv² 1/2 mv_f^(2 )= ⅛ m... 1
- Consider a car moving on a straight road with a speed of 100 m/s. The distance at which a car can be stopped is : (μk = 0.5) b) is the correct option i.e. 1000 When the car is stopped by friction then its retarding force is ma = μR ma = μmg a= μg Consider the equat... 1
- A smooth block is released at rest on a 45∘ incline and then slides a distance The correct answer is a) µk = 1 - 1/n^(2 ) ^(Solution::) On a smooth plane d = ½ (g sinθ) t₁ _( t₁=√( 2dover gsinθ) ) On a rough surface d =... 2
- A marble block of mass 2 kg lying on ice when given a velocity of 6 m/s is stopped by friction in 10s. Then the coefficient of friction is (consider g =10m/s) The correct option is c) 0.06 Explaination: u = 6 m/s v = 0 t =10s a = -f/m = – μmg/m = – μg = -10μ Substituting values in v = u+at 0 = 6 –... 1
- A horizontal force of 10 N is necessary to just hold a block stationary against a wall. The coefficient of friction between the block and the wall is 0.2. The correct option is d) 2N Frictional force balances the weight of the body Frictional force f = μN = mg f= 0.2 X 10 = 2N Therefore, weight... 1
- During the padding of a bicycle, the force of friction exerted by the ground on the two wheels is such that it acts The correct option is a) in the backward direction on the front wheel and in the forward direction on the rear wheel Explaination:: In the b... 1