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Find the value of k for which the equation 3x²+2x+k=0 has distinct and real root.

Given, 3x2 + 2x + k = 0 It’s of the form of ax2 + bx + c = 0 Where, a =3, b = 2, c = k For the given quadratic equation to have real... View Article

If a certain piece of copper is to be shaped into a conductor of minimum resistance, its length (l) and cross-sectional area (a) shall respectively be (a) l and d (b) 2l , d (c) 1/2 , 2d (d) 2l , d/2

The correct answer is (c) 1/2 , 2d From ohm's law and also from resistivity we know that As the area of cross-section decreases the flowing... View Article

Two plane mirrors are inclined at an angle θ. A ray of light is reflected from the first mirror and is then incident on the second mirror from which it is again reflected. What is deviation of incident ray?

A mirror with a flat surface is a plane mirror that reflects light and produces a virtual image without the interference of an inward or outward... View Article

A particle of charge q and mass m moves in a circular orbit of radius r with angular speed ω. The ratio of the magnitude of its magnetic moment to that of its angular momentum depends on 1) ω and q 2) ω, q and m 3) q and m 4) ω and m

The correct answer is 3) q and m A magnetic moment is a quantity that represents the magnetic strength and orientation of a magnet or any... View Article

If a magnet is suspended at an angle of 30º to the magnetic meridian, the dip needle makes an angle of 45º with the horizontal. The real dip is________

If a magnet is suspended at an angle of 30º to the magnetic meridian, the dip needle makes an angle of 45º with the horizontal. The... View Article

A 2kg box sits on a 3kg box which sits on a 5kg box. The 5kg box rests on a table top. What is the normal force exerted by the 5kg box on the 3kg box?

The normal force is equal to the weight of the body during deceleration. When the body is about fall, depends on the location of the body on the... View Article

The width of a river is 1km. The velocity of the boat is 5km/hr . The boat covered the width of the river with the shortest will possible in 15 min. Then the velocity of river stream is:

Given Width of river = 3km/h the velocity of the boat =5km/hr Time is taken for shortest path = 15 mins Find out We have to... View Article

If A and B are two sets such that A ⊂ B, then what is A ∪ B?

The union of two sets X and Y is equal to the set of elements that are present in set X, in set Y, or in both the sets X and Y. This operation... View Article

n identical light bulbs, each designed to draw P power from a certain voltage supply, are joined in series across that supply. The total power which they will draw is

Electric power is the rate at which work is done or energy is transformed into an electrical circuit. Simply put, it is a measure of how much... View Article

The value of sin(45∘+θ)−cos(45∘−θ)

sin(45º+θ)−cos(45º−θ) From the trigonometric identity we know that... View Article

Find the equation of a line that cuts off equal intercepts on the coordinate axes and passes through the point (2, 3).

The point where the line or curve crosses the axis of the graph is called intercept. If a point crosses the x-axis, then it is called the... View Article

Find lcm of 12,48

Least Common Multiple(LCM) is a method to find the smallest common multiple between any two or more numbers. LCM denotes the least common... View Article

Twenty-seven drops of mercury are charged simultaneously to the same potential of 10 volts. what will be potential if all the charged drops are made to combine to form one large drop ?

Let us assume the potential of each small drop = Kq/r = V The volume of n (here 27 small drops) drops = Volume of one big drop. which... View Article

Find the value of x, if the arithmetic mean of 4, 5, 6, 7, 8 and x is 7.

Mean is the most commonly used measure of central tendency. It actually represents the average of the given collection of data. It is applicable... View Article

In the given figure AB||PQ||CD, AB = x units, CD= y units and PQ = z units, then 1/x + 1/y=_______

In Δ FDC and Δ FBA, ∠FDC = ∠FBA [As DC || AB] ∠DFC = ∠BFA [common angle] Hence, ∆FDC ~ ∆FBA by AA criterion for... View Article

A ring of radius 2 m weighs 100 kg. It rolls along a horizontal floor so that its centre of mass has a speed of 20 cm/s. How much work has to be done to stop it?

Given The radius of the ring, r = 2 mMass of the ring, m = 100 kgVelocity of the hoop, v = 20 cm/s = 0.2 m/s Find... View Article

A magnetic dipole of magnetic moment 1.44 A m2is placed horizontally with the north pole pointing towards north. Find the position of the neutral point if the horizontal component of the earth’s magnetic field is 18 μT.

Given M = 1.44 Am2 Find out We have to determine the position of the neutral point Solution We know that for a magnetic... View Article

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