List of top Questions asked in BHU UET- 2009

The longest wavelength line in the Lyman series of the hydrogen spectrum is

In a potentiometer of one- metre length, an unknown emf voltage source is balanced at $60 \,cm$ length of potentiometer wire, while a $3 \,V$ battery is balanced at $45 \,cm$ length. Then the emf of the unknown voltage source is

Figure below show regular haxagons, with charges at the vertices. In which case is the electric field at the centre zero ?

A charge $Q$ is uniformly distributed over a large square plate of copper. The electric field at a point very close to the centre of the plate is 10 $ Vm^{ -1}$. If the copper plate is replaced by a plastic plate of the same geometrical dimensions and carrying the same charge $Q$ uniformly distributed, then the electric field at the point $P$ will be

The least stable free radical is

$1\, g$ of water on evaporation at atmospheric pressure forms $ 1671\,c{{m}^{3}} $ of steam. Heat of vaporisation at this pressure is $ 540\,cal\,{{g}^{-1}} $ . The increase in internal energy is

A charged dust particle of radius $ 5\times {{10}^{-7}}m $ is located in a horizontal electric field having an intensity of $ 6.28\times {{10}^{5}}V{{m}^{-1}} $ . The surrounding medium is air with coefficient of viscosity $ \eta =1.6\times {{10}^{-5}}N-s{{m}^{-2}} $ . If this particle moves with a uniform horizontal speed $ 0.02\,m{{s}^{-1}} $ . Find the number of electrons on it.

Ultraviolet light wavelength $300 \,nm$ and intensity $1.0 \,Wm ^{-2}$ falls on the surface of a photoelectric material. If one percent of the incident photons produce photoelectrons, then the number of photoelectrons emitted per second from an area of $1.0 \,cm ^{2}$ of the surface is nearly

If $N_{0}$ represents Avogadro's number, the number of valence electrons in $4.2 \,g$ of nitride ion $\left( N ^{3-}\right)$ is

The compound that can exhibit geometrical isomerism is

Chlorination of which of the following substance is a substitution reaction?

Which of the following acts as a reducing agent to reduce $ W{{O}_{3}},Mo{{O}_{3}} $ and $ Ge{{O}_{2}} $ into metals?

The process of conversion of ozone into oxygen $\left(2O_{3} \longrightarrow 3O_{2}\right)$ involves following steps $O _{3} {<=>[{\text { Fast }}]} O _{2}+ O$ $O + O _{3} {->[{\text { Slow }}]} 2 O _{2}$ The rate law expression for this process is

Consider the following hypothetical reaction. $A+B \rightleftharpoons C+D ; \,\,\,K_{c}=1 \times 10^{-4}$ Which of the following statements is true for this reaction ? In this reaction,

Dissolution of ammonium chloride in water leads to a cooling sensation. At constant temperature, this process is accompanied by

Natural rubber is

Process used for amplification or multiplication of DNA for finger printing is

The banding patterns of chromosomes $3$ and $6$ of man and chimpanzee show that

Hypersecretion of mineralocorticoids leads to

Ommatidia serve the purpose of photo reception in

Pressure sensitive receptors in the dermis are

Protistan protozoan having nuclear dimorphism is

Renal portal system carries blood

Frenulum is

Colle's fracture is associated with