Class 12th

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A): Sucrose is a disaccharide and a non-reducing sugar.

Reason (R): Sucrose involves glycosidic linkage between C₁ of b-glucose and C₂ of a-fructose.

Choose the most appropriate answer from the options given below:

Which one for the following phenols does not give colour when condensed with phthalic anhydride in presence of conc. H₂SO₄?

The interaction energy of London forces between two particles is proportional to r^x, where r is the distance between the particles. The value of x is:

The Major Product in the above reaction is :

For the given circuit, the power across zener diode is________mW.

A coil in the shape of an equilateral triangle of side 10cm lies in a vertical plane between the pole pieces of permanent magnet producing a horizontal magnetic field 20mT. The troque acting on the coil when a current of 0.2A is passes through it and its plane becomes parallel to the magnetic field will be $\sqrt[]{x}*10^{-5}$ Nm. The value of x is_________.

A circular coil of radius 8.0cm and 20 turns is rotated about its vertical diameter with an angular speed of 50 rad s^-1 in a uniform horizontal magnetic field at 3.0 * 10^-2 T. The maximum emf induced in the coil will be________* 10^-2 volt (rounded off to the nearest integer).

An amplitude modulated wave is represented by   $C_m\left(t\right)=10\left(1+0.2cos12560t\right)sin\left(111*10^{4}t\right)volts.$

The modulating frequency in kHz will be……. .

The electric field in a plane electromagnetic wave is given by

$\overrightarrow{E}=200cos\left[\left(\frac{0.5*10^3}{m}\right)x\left(1.5*10^{11}\frac{rad}{s}*t\right)\right]\frac{V}{m}\widehat{j}$

If this wave falls normally on a perfectly reflecting surface having an area of 100 cm². If the radiation pressure exerted by the E.M. wave on the surface during a 10 minute exposure is $\frac{x}{10^9}\frac{N}{m^2}.$   Find the value of x

An object is placed at a distance of 12 cm from a convex lens. A convex mirror of focal length 15 cm is placed on other side of lens at 8cm as shown in the figure. Image of object. When the convex mirror is removed, a real and inverted image is formed at a position. The distance of the image from the object will be________ (cm).