Latest Posts

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. Instantaneous Speed Formula The instantaneous... 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 Solution 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... 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 Solution Let us assume the angles between two mirrors be θ as per geometry, λ1+λ2=360−20=180+θ 3θ=180º θ=60º... 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... 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. These... 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... 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... 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... 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. Formula of Work The... 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. These... View Article

A charge q is placed at the one vertex of the cube of each side a. The electric flux linked with the cube is ____

According to the Gauss law, the total flux linked with a closed surface is 1/ε0 times the charge enclosed by the... View Article

A satellite is orbiting around the earth. The centripetal force acting on the satellite is F. The force of the satellite on the earth is also F. The net force on the satellite is: (a) F (b) zero (c) 2F (d) F/2

The correct answer is (a) F Solution Centripetal force is the force acting on an object in curvilinear motion directed... View Article

An electric bulb is connected to a 220V power supply line, if the bulb draws a current of 0.5A, calculate the power of the bulb.

Electric power is the rate at which work is done or energy is transformed into an electrical circuit. Simply put,... View Article

19 divisions on the main scale of a vernier callipers coincide with 20 divisions on the vernier scale. If each division on the main scale is of 1 cm, determine the least count of instrument.

A measuring device that is used for the measurement of linear dimensions. It is also used for the measurement of... View Article

Two straight parallel lines are cut by a transversal. If the measures of two corresponding angles are (2b+15)^oand(3b−7)^o. Find the value of ‘b’.

When a transversal intersects two parallel lines, the corresponding angles so formed will be equal Corresponding angles are the angles that... View Article

Two bulbs are rated (P1, V) and (P2, V). If they are connected (i) in series and (ii) in parallel across a supply V Find the power dissipated in the two combinations in terms of P1 and P2.

Electric power is the rate at which work is done or energy is transformed into an electrical circuit. Simply put,... View Article

Internal energy of n₁moles of hydrogen at temperature T is equal to the internal energy of n₂ moles of helium at temperature 2T. Then the ratio n₁/n₂ is

The number of independent ways in which a molecule of gas can move is called the degree of freedom. It... View Article

Two identical prisms p1 and p2 are placed in such a way that the second prism is placed in an inverted position with respect to the first prism. what will be observed on the screen?

In optics, a prism is defined as a transparent solid body that has three rectangular lateral surfaces and two triangular... View Article

A massive disc of radius R is moved with a constant velocity m on a frictionless table. Another small disc collides with it elastically with a speed ofv0=0.3m/s, the velocities of the discs being parallel. The distance (shown in the figure) is equal to R/2, friction between the discs is negligible. For which u (in m/s) will the small disc move perpendicularly to its original motion after the collision?

Elastic collission An elastic collision is a collision in which there is no net loss in kinetic energy in the... View Article

«
1
…
559
560
561
562
563
…
5,472
»