The resultant force on the square current loop PQRS due to a long current-carrying conductor will be:
The forces will be equal and opposed because the currents in the lengths PQ and RS are equal and opposite.... View Article
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An equilateral triangular loop of wire of side ℓ carries a current i. The magnetic field produced at the circumcentre of the loop is :
If considered l is the triangle’s side, the circumcenter’s distance from each of the triangle’s sides equals r= I√3/6. The... View Article
Two Magnets of equal magnetic moments M each are placed as shown in figure. The resultant magnetic moment isa) M b) √2M c) √3M d) M/2
Answer: (a)M Explanation Due to the fact that magnetic moments are directed along SN, the angle between M and M... View Article
What is the correct relation between common base current gain α and common emitter current gain β ?
Answer: β = α/1−α Explanation We have asked to determine the relationship between the current gain α in Common Base... View Article
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... 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... View Article
For an RLC circuit driven with voltage of amplitude vm 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) Explanation The quality factor is defined as the voltage magnification of the circuit at resonance Quality Factor Q... 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 Explanation Only when the magnetic flux in the loop changes does an emf occur. When the loop 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 =... 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... 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... 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... 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.... 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... 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)... 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... 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... 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 SI units of a and b ρ = a + bx Unit of... 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... 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... View Article
