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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

The true value of angle of dip at a place is 60º the apparent dip in a plane inclined at an angle of 30 ºwith magnetic meridian is

A magnetic meridian is defined as a line on the earth’s surface approximating a great circle, which passes through the north and the south... View Article

Two plane mirrors are inclined to each other such that a ray of light incident on the first mirror (M1) and parallel to the second mirror (M2) is finally reflected from the second mirror (M2) parallel to the first mirror (M1) . The angle between the two mirrors will be: (a) 90° (b) 45° (c) 75° (d) 60°

The correct answer is (d) 60º Let us assume the angles between two mirrors be θ as per geometry, ... View Article

Assertion: In electromagnetic waves electric field and the magnetic field are perpendicular to each other. Reason: Electric field and the magnetic field are self-sustaining. (a) Both the assertion and reason are correct and the reason is the correct explanation of the assertion (b) Both the assertion and reason are correct but reason is not the correct explanation for assertion (c) assertion is correct but reason is incorrect (d) Both the assertion and reason are incorrect

The correct answer is (b) Both the assertion and reason are correct but reason is not the correct explanation for assertion Electromagnetic... View Article

A force F is given by F=at+bt², where t is time, the dimensions of a and b are

Dimensional analysis is the practice of checking relations between physical quantities by identifying the dimensions of the physical quantities.... View Article

A current of 1 A through a coil of inductance of 200 mH is increasing at a rate of 0.5 A s ^{−1^{. The energy stored in the inductor per second is then}}

The magnetic field surrounding an inductor stores energy as current flows through the field. If the amount of current is slowly decreased, the... View Article

The maximum refractive index of a prism which permits passage of the light through it when the refracting angle of the prism is 90 ^∘, 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 stone of mass 5 kg falls from the top of a cliff 50 m high and buries into 1 m in sand. Find the average resistance offered by the sand and the time it takes to penetrate.

Given M = 5 kgh = 50 m Find out We have to determine the average resistive force offered by sand and time takes to penetrate. Solution... View Article

A rigid body moves a distance of 10m along a straight line under the action of a force of 5 N. lf the work done by this force on the body is 25 joules, the angle which the force makes with the direction of motion of the body is

Work is said to be done when an object experiences displacement. It is represented by W. The work formula is articulated as W = (F cos... View Article

If R, C and L be the fundamental quantities such as resistance capacitance and inductance in a circuit in W then find the dimensional formula for resistance and capacitance.

Dimensional analysis is the practice of checking relations between physical quantities by identifying the dimensions of the physical quantities.... View Article

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