An infinitely long straight wire is bent as shown in figure. The circular portion has a radius of 10 cm with its center O at a distance r from the straight part. The value of r such that the magnetic field at the center O of the circular portion is zero will be :-

Two cylindrical straight and very long nonmagnetic conductors A and B, insulated from each other, carry a current I in the positive and the negative z–direction respectively. The direction of magnetic field at origin is

Current i = 2.5 A flows along the circle (here x & y in cm) as shown. Magnetic field at point (0, 0, 4 cm) is

There are constant electric field & magnetic field present between plates P and . A particle of mass m is projected from plate P' along y axis with velocity v₁ . After moving on the curved path, it passes through point A just grazing the plate P with velocity v₂ . The magnitude of impulse(i.e. )provided by magnetic force during the motion of particle from origin to point A is :–

In a set of reactions, acetic acid yields a product [C].

In a set of reactions, m-bromo benzoic acid gave a product ‘D’. Identify the product.

 Compound C in the above reaction is

Compounds of general formula are called

The liquid in the watch glass in the following figure is :-

we can summarize the sum of GP formulas as follows:

• S∞ = a / (1 - r) when |r| < 1
• S∞ = ±∞, when |r| ≥ 1

 The IUPAC name of ‘B’ is

Match the reactant in Column-I with the reaction in Column-II

A semi circular current carrying wire having radius R is placed in plane with its centre at origin 'O'. There is non–uniform magnetic field (here B0 is +ve constant) is existing in the region. The magnetic force acting on semicircular wire will be along

A particle moving with velocity v having specific charge (q/m) enters a region of magnetic field B having width at angle to the boundary of magnetic field. Find the angle in the diagram.

A charged particle enters a uniform magnetic field perpendicular to its initial direction travelling in air. The path of the particle is seen to follow the path in figure. Which of statements 1–3 is /are correct?
1) The magnetic field strength may have been increased while the particle was travelling in air
2) The particle lost energy by ionizing the air
3) The particle lost charge by ionizing the air

Collin’s reagent causes the conversion