Class 12th

Statement A: In intrinsic semiconductors, conductivity is mainly due to the breakage of covalent bonds.

Statement B: In extrinsic semiconductors, the conductivity is mainly due to the addition of impurities.

An AND gate can be prepared by repetitive use of

a) NOT gate (b) OR gate            (c) NAND gate                 (d) NOR gate

Which of the following is not a common component of photochemical smog?

Consider the following statements

(I)  Histamine is a potent vasodilator

(II) Brompheniramine is an antihistamine

(III) Tranquilizers and analgesics are neurologically active drugs

The correct statements among the following are

Identify the incorrect statement.

A rectangular coil of wire of $500$ turns of area $10*5c{m}^2$ carries a current of $2A$ in a magnetic field of induction $2*{10}^{-3}T$ . If the plane of the coil is parallel to the field. The torque on the coil is $\left(inNm\right)$  

Nitroethane when heated above 573 K yields

An object of height 1.5cm is placed on the axis of a convex lens of focal length 25cm. A real image is formed at a distance of 75cm from the lens. The size of the image will be

In which of the following alcohols, dehydration takes place most readily in acidic medium?

The superposition of waves can result in