Class 12th

A small bar magnet is moved through a coil at constant speed from one end to the other. Which of the following series of observations will be seen on the galvanometer G attached across the coil?

Three positions shown describe:

(a) The magnet's entry

(b) Magnet is completely inside and

(c) Magnet's exit

An infinitely long hollow conducting cylinder with radius R carries a uniform current along its surface. Choose the correct representation of magnetic field (B) as a function of radial distance (r) from the axis of cylinder.

Match the $C_p/C_V$ ratio for ideal gases with different type of molecules:

Match the correct option?

A two point charges $4q$ and $-q$ are fixed on the $x$ -axis at $x=-\frac{d}{2}$ and $x=\frac{d}{2}$ , respectively. If a third point charge ' $q$ ' is taken from the origin to $x=d$ along the semicircle as shown in the figure, the energy of the charge will:

Take the breakdown voltage of the zener diode used in the given circuit as $6\mathrm{V}$ . For the input voltage shown in figure below, the time variation of the output voltage is: (Graphs drawn are schematic and not to scale)

A Tennis ball is released from a height $h$ and after freely falling on a wooden floor it rebounds and reaches height $\frac{h}{2}$ . The velocity versus height of the ball during its motion may be represented graphically by:

(graphs are drawn schematically and on not to scale)

The value of the integral ${\displaystyle \underset{0}{\overset{\frac{\pi }{2}}{\int }}60\frac{sin\left(6x\right)}{sinx}}$ dx is equal to…….

A bag contains 4 white and 6 black balls. Three balls are drawn at random from the bag. Let X be the number of white balls, among the drawn balls. If ${\sigma }^2$ is the variance of X, then $100{\sigma }^2$ is equal to………

Let z = a ib, b $\ne$ 0 be complex numbers satisfying z² = $\overline{z}.2^{1-\left|z\right|}.$ Then the least value of n $\in$ N, such that zn = ${\left(z+1\right)}^n,$ is equal to………