The inductance of a closed-packed coil of 400 turns is 8 mH. A current of 5 mA is passed through it. The magnetic flux through each turn of the coil is
The graph between ratio of speed of electron in nth orbit to radius of nth orbit and n for Bohr’s hydrogen atom is
A long straight wire is placed along the axis of a circular ring of radius R. The mutual inductance of this system is
A steel wire having a radius of 2.0 mm, carrying a load of 4 kg, is hanging from a ceiling. Given that g=3.1π m s−2, what will be the tensile stress that would be developed in the wire?
A vertical spring with force constant k is fixed on a table. A ball of mass m at a height h above the free upper end of the spring falls vertically on the spring and at some instant, it compresses the spring by a distance d. The net work done by all the forces up to that instant is
Two large conducting plates having surface charge densities + σ & –σ are fixed d distance apart. A small test charge q of mass m is attached to two identical springs as shown in the adjacent figure. The charge q is now released from rest with springs in natural length. Then q will [neglect gravity]:
A boy throws a ball upwards with velocity u = 15 m s−1. The wind imparts a horizontal acceleration of 3 m s−2 to the left. The angle θ¸ at which the ball must be thrown so that the ball returns to the boy's hand is (use g = 10 m s−2)
A thin wire loop carrying a current I is placed in a uniform magnetic field B pointing out of the plane of the coil as shown in the figure. The loop will tend to
A galvanometer of 50 Ω resistance has 25 divisions. A current of 4 x 10-4 A gives a deflection of one division. To convert this galvanometer into a voltmeter having a range of 25 V, it should be connected with a resistance of
In an n-p-n transistor amplifier, the collector current is 9 mA. If 90% of the electrons from the emitter reach the collector, then
In the following reaction, which choice has value twice that of the equivalent mass of the oxidising agent SO₂ + H₂O → 3S + 2H₂O
Among the trihalides of nitrogen which one is most basic?
The chemical equilibrium of a reversible reaction is not influenced by
The interionic distance for cesium chloride cystal will be
Which species represents the electrophile in aromatic nitration?
Which of the following shows maximum no. of oxidation states?
The linear inequations for which the shaded area in the following figure is the solution set, are
A differentiable function f is defined as f(x3) = 4x4, for all x. The value of f'(8) is
The eccentricity of the hyperbola in the standard form passing through (3, 0) and (3√2, 2) is
All the real values of m such that both roots of the equation x2 − 2mx + m2 − 1 = 0 are greater than −2 and less than 4 lies in
If the roots of the equation x2 - bx + c = 0 are two consecutive integers, then b2 - 4c is equal to
If a, b and c are in AP, then which of the following is false?
If p, q and r are negative distinct real numbers, then the determinant