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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 coin is tossed thrice. Find the probability of getting (i) exactly two heads (ii) at least two tails.

Probability is the measurement of chances – the likelihood that an event will occur. If the probability of an event is high, it is more... View Article

The midpoint of the line segment joining A (2a, 4) and B (-2, 3b) is C (1, 2a + 1). Find the values of a and b.

To find the midpoint of the straight line in a graph, we use this midpoint formula that will enable us to find the coordinates of the midpoint of... View Article

If A is an acute angle in a right △ABC, right-angled at B, then the value of sinA+cosA is

Given A is an acute angle in a right △ABC, right-angled at B Find out We have to determine the value of sinA+cosA Solution... 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

The angle between transmission axis of a polarizer and an analyser is 30°. the percentage of polarized light passing through analyser is (intensity of polarized light = i0)

Malus’ law states that the intensity of plane-polarized light that passes through an analyzer varies as the square of the cosine of... View Article

If a and b are the roots of the equation x²+ax-b=0 then find a and b.

A quadratic equation is an equation of degree 2, meaning that the highest exponent of this function is 2. The standard form of a quadratic is y... View Article

A particle of mass 2 kg is moving westward with velocity 15m/s. in 10 seconds the velocity changes to 15m/ s northwards. the force acting on the body is_____

Acceleration is defined as the rate of change of velocity with respect to time. Acceleration formula is given as:... View Article

The electric field is 100V/m, at a distance of 20cm from the centre of a dielectric sphere of a radius of 10cm. Then E at 3cm distance from the centre of the sphere is:

Given According to the given details Electric field from distance = 100 N/mR = Radius = 20m r = 10cm Find out We have to determine the... View Article

A fish is at the depth of 30 cm below the surface of water. if refractive index of water is 5/3,then the distance between the fish and its image is

The refractive index is the measure of bending of a light ray when passing from one medium to another. It can also be defined as the ratio of the... View Article

A projectile is projected with a velocity v making an angle with horizontal. Mention the equations for maximum height and time of flight for a projectile.

A projectile is any object thrown into space upon which the only acting force is gravity. The primary force acting on a projectile is... View Article

A half ring of radius R has a charge of λ per unit length. The potential at the centre of the half ring is (a) k λ/R (b) k λ/πR (c) k πλ/R (d) kπλ

The correct answer is (d) kπλ According to the given data the total charge on the half ring is πRλ. As all points on the... View Article

A concave mirror of focal length ‘f’ produces an image ‘n’ times the size of the object. If the image is real then the d distance of the object from the mirror is

The correct option is B (n+1/n)f Magnification refers to the increase in image size created by spherical mirrors in comparison to the... View Article

A hemisphere shell is uniformly charged positively. The electric field at a point on a diameter away from the centre (inside the boundary of hemispherical shell) is directed (a) perpendicular to the diameter (b) parallel to the diameter (c) at an angle tilted towards the diameter (d) at an angle away from the diameter

A hemisphere shell is uniformly charged positively. The electric field at a point on a diameter away from the centre (inside the boundary of... View Article

A body moves from rest with a constant acceleration of 5 m/s². Its instantaneous speed (in m/s) at the end of 10 sec is

instantaneous speed at any given time is the magnitude of instantaneous velocity at that time. The instantaneous speed formula... View Article

A bulb and a capacitor are in series with an ac source. On increasing frequency how will glow of the bulb (a) increases (b) decreases (c) no change (d)quenches

The correct answer is (a) increases The definition of capacitive reactance states that it is the opposition offered by... View Article

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