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A particle executes S.H.M with amplitude ‘a’ and time period T. The displacement of the particle from the mean position when its speed is half of the maximum speed is √xa/2. The value of x is ________

Answer: 3 For a particle executing S.H.M V = ω√(a2 - x2) Given V = Vmax/2 ⇒ aω/2 a2ω2/4 = ω2a2 - ω2x2 x... View Article

1 mole of a rigid diatomic gas performs a work of Q/5. when heat Q is supplied to it. The molar heat capacity of the gas during this transformation is xR/8. The value of x is _________.

Answer: 25 From thermodynamics law: ∆Q = ∆U + ∆W …..(1) Q = nCv∆T + Q/5 Q – Q/5 = 1 × (5/2)R × ∆T Q = (25/8)... View Article

If the highest frequency modulating a carrier is 5 kHz, then the number of AM broadcast stations accommodated in a 90 kHz bandwidth are ___________.

Answer: 9 No. of station = Band width/2× Highest Bandwidth ⇒ 90/2×5 ⇒ 9... View Article

Given below are two statements:

Given below are two statements: Statement – I: An electric dipole is placed at the centre of a hollow sphere. The flux of the electric... View Article

The internal energy (U), pressure (P) and volume (V) of an ideal gas are related as U = 3PV + 4. The gas is:

a. polyatomic only b. monoatomic only c. either monoatomic or diatomic d. diatomic only. Answer: (a) U = 3 PV + 4 (f/2) PV = 3PV + 4 ∴u =... View Article

The length of the metallic wire is l_1 when the tension in it is T_1. It is l_2 when the tension is T_2. The original length of the wire will be:

a. (l1 + l2)/2 b. (T1l1 - T2l2)/(T2-T1) c. (T2l1 + T1l2)/(T2+T1) d. (T2l1 - T1l2)/(T2-T1) Answer: (d) From young’s modulus relation (y =... View Article

An aeroplane with its wings, spread 10 m, is flying at a speed of 180 km/h in a horizontal direction. The total intensity of the magnetic field at that part is 2.5 × 10^–4 Wb/m² and the angle of dip is 60⁰. The emf induced between the tips of the plane wings will be:

a. 88.37 mV b. 62.50 mV c. 54.125 mV d. 108.25 mV Answer: (d) E = Bvertical lv sin 600 = Bv/B √3/2 = Bv/B Bv = √3B/2 E=... View Article

Given below are two statements: Statement (1):- A second’s pendulum has a time period of 1 second. Statement (2):- It takes precisely one second to move between the two extreme positions.

In light of the above statements, choose the correct answer from the options given below. a. Both Statement I and Statement II are false b.... View Article

A wire of 1Ω has a length of 1 m. It is stretched till its length increases by 25%. The percentage change in resistance to the nearest integer is:

a. 25% b. 12.5% c. 76% d. 56% Answer: (d) ∵R ∝ l/A ……….(i) For stretched or compressed wire Volume =... View Article

Two masses A and B, each of mass M are fixed together by a massless spring. A force acts on mass B as shown in the figure. If mass A starts moving away from mass B with acceleration ‘a’, then the acceleration of mass B will be:

Two masses A and B, each of mass M are fixed together by a massless spring. A force acts on mass B as shown in the figure. If mass A starts... View Article

The recoil speed of a hydrogen atom after it emits a photon in going from n = 5 state to n = 1 state will be:

a. 4.17 m/s b. 4.34 m/s c. 219 m/s d. 3.25 m/s Answer: (a) Momentum (P) = ΔE/C ⇒ (13.6 - 0.54)eV/3×108 mv =... View Article

Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R.

Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R. Assertion A: For a simple microscope, the... View Article

If ‘C’ and ‘V’ represent capacitance and voltage respectively then what are the dimensions of λ where C/V = λ?

a. [M-2L-4I3T7] b. [M-2L-3I2T6] c. [M-1L-3I-2T-7] d. [M-3L-4I3T7] Answer: (a) ∴ V = w/q and C = q/V Dimension of C/V ⇒ q2/Vw ⇒... View Article

An inclined plane making an angle of 30⁰ with the horizontal is placed in a uniform horizontal electric field 200 N/C as shown in the figure. A body of mass 1 kg and charge 5 mC is allowed to slide down from rest from a height of 1 m. If the coefficient of friction is 0.2, find the time taken by the body to reach the bottom.

[g = 9.8m/s2, sin 300 = 1/2; cos 300 = √3/2] a. 2.3 s b. 0.46 s c. 1.3 s d. 0.92 s Answer: (c) Fnet = mg sinθ - (μN + q E... View Article

Draw the output Y in the given combination of gates.

Draw the output Y in the given combination of gates. Answer: (1) Find output expression... View Article

A scooter accelerates from rest for time t₁ at constant rate α₁ and then retards at constant rate α₂for time t₂ and comes to rest. The correct value of t₁/t₂ will be:

a. (α1 + α2)/α2 b. α2/α1 c. (α1 + α2)/α1 d. α1/α2 Answer: (b) From given information:... View Article

A particle executes S.H.M., the graph of velocity as a function of displacement is:

a. a circle b. a parabola c. an ellipse d. a helix Answer: (c) For a body performing SHM, relation between velocity and displacement v =... View Article

A radioactive sample is undergoing α decay. At any time t₁, its activity is A and at another time t₂, the activity is A/5. What is the average lifetime for the sample?

a. (t2 - t1 )/ln 5 b. ln(t2 + t1) /2 c. (t1 - t2)/ln 5 d. ln5/(t2 - t1) Answer: (a) For activity of radioactive sample : A =... View Article

The incident ray, reflected ray and the outward drawn normal are denoted by the unit vectors

The incident ray, reflected ray and the outward drawn normal are denoted by the unit vectors respectively. Then choose the correct relation for... View Article

Find the peak current and resonant frequency of the following circuit (as shown in the figure)

Find the peak current and resonant frequency of the following circuit (as shown in the figure) a. 0.2 A and 100 Hz b. 2 A and 50 Hz... View Article

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