Physics NCERT Exemplar Solutions Class 12th Chapter Four

The magnetic field at the centre of current carrying circular loop is B₁. The magnetic field at a distance of $\sqrt[]{3}$ times radius of the given circular loop from the center on its axis is B₂. The value of B₁/B₂ will be

A triangular shaped wire carrying 10 A current is a uniform magnetic field of 0.5T, as shown in figure.

The magnetic force on segment CD is (Given BC = CD = BD = 5cm).

Starting from the origin at time $t=0$ , with initial velocity $5\hat{j}{\mathrm{m}\mathrm{s}}^{-1}$ , a particle moves in the $x$$-y$ plane with a constant acceleration of $(10\hat{i}+4\hat{j}){\mathrm{m}\mathrm{s}}^{-2}$ . At time $t$ , its coordinates are $(20$ $\left.m,y_{0}m\right)$ . The values of $t$ and $y_0$ are, respectively:

A wire $A$ , bent in the shape of an arc of a circle, carrying a current of $2\mathrm{A}$ and having radius $2\mathrm{c}\mathrm{m}$ and another wire $B$ , also bent in the shape of arc of a circle, carrying a current of $3\mathrm{A}$ and having radius of $4\mathrm{c}\mathrm{m}$ , are placed as shown in the figure. The ratio of the magnetic fields due to the wires $A$ and $B$ at the common centre $O$ is:

The specific heat of water $=4200\mathrm{J}{\mathrm{k}\mathrm{g}}^{-1}{\mathrm{K}}^{-1}$ and the latent heat of ice $=3.4*{10}^5\mathrm{J}{\mathrm{k}\mathrm{g}}^{-1}$ . 100 grams of ice at $0^{\circ }\mathrm{C}$ is placed in $200\mathrm{g}$ of water at ${25}^{\circ }\mathrm{C}$ . The amount of ice that will melt as the temperature of water reaches $0^{\circ }\mathrm{C}$ is close to (in grams):

A singly ionized magnesium atom (A = 24) ion is accelerated to kinetic energy 5 ke V, and is projected perpendicularly into a magnetic field B of the magnitude 0.5 T. The radius of path formed will be ________cm.

Motion of a particle in x – y plane is described by a set of following equations x = 4sin $\left(\frac{\pi }{2}-\omega t\right)$ m and y = 4sin $\left(\omega t\right)m.$ The path of a particle will be

A ball is projected with kinetic energy E, at an angle of 60° to the horizontal. The kinetic energy of this ball at the highest point of its flight will become:

A smooth circular groove has a smooth vertical wall as shown in figure. A block of mass m moves against the wall with a speed v. Which of the following curve represents the correct relation between the normal reaction on the block by the wall (N) and speed of the block (v)?

A deuteron and a proton moving with equal kinetic energy enter into to a uniform magnetic field at right angle to the field. If r_d and r_p are the radii of their circular paths respectively, then the ratio $\frac{r_d}{r_p}$  will be $\sqrt[]{x}:1$  where x is……….