New Concepts/Shortcuts 3

Question 1

shortcut for acceleration, friction exerted, and KE of a rolling object

and what’s the work done friction!?

Answer 1

Question 2

how to approach this q!?

Answer 2

the total energy would be constant here

so find the total energy due to spring. rotational, translation, etc and then differentiate it with respect to t

then we would have an expression with respect to alpha and stuff where we can find the angular frequency expression

Question 3

Trick for rotational pulley problems(finding alpha)

Answer 3

Question 4

polytropic process formula for work done, molar heat capacity, heat exchange

Answer 4

Question 5

what to do if we have a algebra+trigo equation and we have to find the number of solutoin

Answer 5

draw the graph of trigo and algebra part and find intersection points

Question 6

expansion

Answer 6

Question 7

damped equation formula from cos formulae

and also the angular frequency formula in a damped oscillation

Answer 7

Question 8

potential gradient formula

Answer 8

where Ro is the resistance of the 1 m wire

and R1 is the internal resistance of the main Emf battery(not the one we have to find(

Question 9

what if we have a number whose remainder is something other than 1

Answer 9

repeat the process till we have a 1 as a remainder

Question 10

what forms a poorly soluble precipitate with reaction with Ph-SO2Cl

Answer 10

primary and secondary amine forms poorly soluble ppt wit h reaction with R-SO2Cl

Question 11

Let A₁, A₂, …, An, n arithmetic means are inserted between two numbers ‘a’ and ‘b’ such that a, A₁, A₂, …, An, b from an AP.

write the formula for Ar

Answer 11

Question 12

do we use end correction in the resonance tube?

Answer 12

only if we have to find the length of resonance

but if we have to find velocity, it isnt counted as the end correction gets subtracted in l2-l1

Question 13

What’s the unit of planks constant?

Answer 13

Js

Question 14

at t=inf P.D across inductor=?

Answer 14

0

Question 15

Answer 15

Question 16

benzene with an excess of Cl2 in the presence of AlCl3 forms?

Answer 16

Question 17

friedal craft reactin doesnt happens with___-

Answer 17

partial double bond character

Question 18

nu of photons/spectral lines if we have the ending and starting orbit number

Answer 18

Question 19

which series lies in visible,IR and UV region

Answer 19

Question 20

time taken for photocurrent is in the order

Answer 20

10^ -9

Question 21

gunmetal consists of

Answer 21

Cu, Sn,Zn

Question 22

epoxides in the acid medium have which kind of reaction and what if it’s in basic medium!?

Answer 22

Question 23

What’s the perfect condition with respect to the magnetic susceptibility for a diamagnetic material?

Answer 23

magnetic susceptibility = -1 for a diamagnetic material

Question 24

curie’s temperature formula for ferromagnetic and paramagnetic material

Answer 24

Question 25

draw the hysteresis graph

and whats coercivity and retentivity

Answer 25

Question 26

star delta method for capacitors

Answer 26

Question 27

relation between E,C,B with vectors

Answer 27

Question 28

kjeldahl’s method shortcut

Answer 28

ignore the NaOHif not given

subtract the 2MV of H2SO4 from MV of the NaOH which would be equal to x

put it in the formula % of N = x * 1.4/w

w being the weight of compound given

Question 29

what are Lissajous figures and how to solve Lissajous figures questions

Answer 29

figures formed by the superposition of two perpendicular time-varying functions

two find the figures
eliminate the t and find the equation between x and y and then we can find the figure shapes

Question 30

eg of homogenous catalysis

Answer 30

Question 31

whats heterogenous catalysis

Answer 31

The catalytic process in which the reactants and the catalyst are in different phases is known as heterogeneous catalysis.

Question 32

eg of heterogeneous catalysis

Answer 32

Question 33

explain the diffusion of reaction products away from the catalyst surface mechanism

Answer 33

Diffusion of reaction products away from the catalyst’s surface. The surface of the catalyst unlike the inner part of the bulk, has free valencies which provide the seat for chemical forces of attraction. When a gas comes in contact with such a surface, its molecules are held up there due to loose chemical combination. If different molecules are adsorbed side by side, they may react with each other resulting in the formation of new molecules. Thus, formed molecules may evaporate leaving the surface for the fresh reactant molecules.

Question 34

the catalytic activity reactivity variation acc to grps

Answer 34

It has been found that for hydrogenation reaction, the catalytic activity increases from Group 5 to Group 11 metals with maximum activity being shown by groups 7-9 elements of the
periodic table

Question 35

how does CO with H2 react with different catalysts

Answer 35

Question 36

why are zeolites good shape-selective catalysts?

Answer 36

Zeolites are good shape-selective catalysts because of their honeycomb-like structures

Question 37

why are zeolites good shape-selective catalysts?

Answer 37

Zeolites are good shape-selective catalysts because of their honeycomb-like structures

Question 38

on what does the reaction taking place in zeolites depend upon?

Answer 38

The reactions taking place in zeolites depend upon the size and shape of reactant and product molecules as well as upon the pores and cavities of the zeolites.

Question 39

how are zeolites used in petrochemical industry

Answer 39

Zeolites are being very widely used as catalysts in petrochemical industries for the cracking of hydrocarbons and isomerization. An important zeolite catalyst used in the petroleum industry is ZSM-5. It converts alcohols directly into gasoline (petrol) by dehydrating them to give a mixture of hydrocarbons.

Question 40

define enzymes

Answer 40

Enzymes are complex nitrogenous organic compounds which are produced by living plants and animals.

They are actually protein molecules of high molecular mass and form colloidal solutions in water.