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The stationary waves are produced in a 20 m long stretched string fixed at both ends. if the string vibrates in 10 loops and wave velocity in the string is 20 m/s, then the frequency of the wave is ?

The standing waves are formed by the superposition of two harmonic waves of equal amplitude and frequency travelling through the medium in the... View Article

The network shown in the figure is part of a complete circuit. If at a certain instant, the current I is 5A and it is decreasing at a rate of 10³As⁻¹ then VB−VA equals

As we move from point A to point B, we'll construct the voltage drop equation. VA − iR + V + L di/dt = VB VA−5 × 1 + 15 − 5 × 10−3 × (−103) =... View Article

For an RLC circuit driven with voltage of amplitude v_m and frequency ω₀= 1/√LC the current exhibits resonance. The quality factor, Q is given by. a) R/ω₀C b) CR/ω₀ c) ω₀L/R d) ω₀R/L

Answer: (c) The quality factor is defined as the voltage magnification of the circuit at resonance Quality Factor Q = 1/R √L/C It is... View Article

A conducting loop is placed in a uniform magnetic field, with its plane perpendicular to the field. An emf is induced in the loop if a) It is rotated about its axis b) It is rotated about its diameter c) It is not moved d) It is given translational motion in the field

Answer: B Only when the magnetic flux in the loop changes does an emf occur. When the loop is revolved around a diameter, this is... View Article

A body of mass 5 kg is suspended by a spring balance on an inclined plane as shown in figure. The spring balance measure

Acceleration of the body down the rough inclined plane =gsinθ ∴ Force applied on spring balance =m g sinθ = 5 × 10... View Article

A capacitor of capacitance C is charged to a potential difference V from a cell and then disconnected from it. A charge + Q is now given to its positive plate. The potential difference across the capacitor is now :

The capacitor's initial charge is q=CV. As a result, the capacitor's positive plate will receive a charge of +q, while the negative plate will... View Article

If A lies in the third quadrant and 3tanA – 4 = 0 then 5sin2A + 3sinA + 4cosA is equal to (1) 0 (2) -24/5 (3) 24/5 (4) 48/5

Answer: (1) 0 3tanA - 4 = 0 3tanA = 4 tanA = 4/3 tan2A = 16/9 sec2A = 1 + tan2A sec2A = 1 + 16/9 = 25/9 Since A lies in third quadrant... View Article

Which of the following chemical compound is planar? (1) XeF2 (2) XeO3F (3) XeO2F2 (4) XeF4

Answer: (4) XeF4 XeF4 is square planar molecule having two non-bonding electron pair, one is located above and one is located below the plane... View Article

A particle of charge q, mass m and kinetic energy T enters a transverse uniform magnetic field of induction B. After 3 s, the kinetic energy of the particle will be (1) 3T (2) 2T (3) T (4) 4T

Answer: (3) T Magnetic field does not change the kinetic energy of charged particles. So, the energy will be T. The magnitude of the particle's... View Article

A person of mass m is standing on one end of a plank of mass M and length L and floating in water. The person moves from one end to another and stops. The displacement of the plank is (1) Lm/(m + M) (2) L(M + m) (3) (M + m)/Lm (4) LM/(m + M)

Answer: (1) Lm/(m + M) Let Displacement of plank is x Velocity of person with respect to plank is v Velocity of plank is opposite... View Article

A line intersects the y-axis and x-axis at points P and Q respectively. If the mid point of PQ is (2, -5), then find the coordinates of P and Q.

Answer: Let the co-ordiantes of P be (x1, ) and Q be (x2, y2) Midpoint of PQ = (2, -5) By midpoint formula, x =( x1 + x2)/2 and y = (y1+... View Article

The pressure exerted by a perfect gas is equal to ____________(1) 2/3 of mean kinetic energy. (2) half of mean kinetic energy per unit volume. (3) mean kinetic energy per unit volume (4) 2/3 of mean kinetic energy per unit volume.

Answer: (4) 2/3 of mean kinetic energy per unit volume. As per the kinetic theory of gases, the P exerted by a gas of density ρ and r.m.s... View Article

Let O(0, 0), P(3,4), Q(6, 0) be the vertices of the triangle OPQ. The point R inside the triangle OPQ is such that the triangles OPR,PQR, OQR are of equal area. The coordinates of R are (1) (4/3,3) (2) (3,2/3) (3) (3,4/3) (4) (4/3,2/3)

Answer: (3) (3,4/3) Let us consider the coordinate of R be (x, y) Given: Area of triangle OPR, PQR, and OQR are same . 3y - 4x = 24 - 4x -... View Article

A rod of length (L) is placed along the x-axis between x = 0 and x = L. The linear density (mass/length) ρ of the rod changes with the distance x from the origin as ρ = a + bx. (1) Find the SI units of a and b. (2) Find the mass of the rod in terms of a, b and L.

Answer: Given ρ = a + bx ρ = a + bx Unit of linear density (ρ) = mass/length SI unit of a = mass/length SI unit of b =... View Article

A ball of mass m approaches a wall of mass M (>> m) with the speed 4 m/s along normal to the wall. The speed of wall is 1m/s towards the ball . The speed of the ball after an elastic collision with the wall is (1) 5 m/s away from the wall (2) 3 m/s away from the wall (3) 9 m/s away from the wall (4) 6 m/s away from the wall

Answer: (4) 6 m/s away from the wall Mass of wall is very large compared to the mass of the ball, hence after collision, velocity of the wall... View Article

How find interest rate?

Answer: The interest rate formula is used to calculate the amount of money that must be repaid on a loan as well as the interest earned on fixed... View Article

The osmotic pressure of blood is 7.65 atm. at 310 K. An aqueous solution of Glucose that will be isotonic with blood is what wt/vol?

Answer: 54.162g/liter Osmotic pressure can be defined as the minimum pressure that must be applied to a solution to halt the flow of solvent... View Article

According to Bohr orbital theory, the angular momentum of electron in 5th orbit is (1) 25h/π (2) 1h/π (3) 10h/π (4) 2.5h/π

Answer: 4) 2.5h/π Bohr theory Applicable to modified the atomic structure model by explaining that electrons move in fixed orbitals and not... View Article

A watch gains 5 seconds in 3 minutes was set right at 7 A.M In the afternoon of the same day, when the watch shows quarter past 4 o’clock, the true time is ______________.

Answer: 4 P.M Time from 7 A.M to 4.15 P.M = 9 hours 15 minutes = 37/4 3 minutes 5 seconds of the clock = 3 minutes of the correct clock 37/720... View Article

In faintly or neutral alkaline solution, 8 moles of permaganate anion quantitative oxidize thiosulphate anions to produce X moles of a sulphur containing product. The magnitude of X is______

Answer: 6 moles A solution of a soluble base with pH greater than 7 is called as an alkaline solution. Solutions having the value of pH equal to... View Article

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