List of practice Questions

In a reaction involving ring substitution of $C_6H_5Y$ the major product is meta isomer. The group Y can be
In a population per capita birth rate is $0.15$ and per capita death rate is $0.08$ during a unit time period. What is the value of $r$ (intrinsic rate of natural increase) for the given population ?
In a projectile motion, the velocity is perpendicular to acceleration at.
In a plane e.m. wave, magnetic field oscillates sinusoidally with frequency 1 GHz. If its amplitude is $16 \times 10^{-8}$ T then amplitude of electric field is
In a polymer sample, 30% of molecules have a molecular mass of 20,000, 40% have 30,000 and the rest 60,000. What is the weight average molecular mass of the polymer ?
In a polymerase chain reaction, temperature required for the steps (i) Denaturation, (ii) Annealing and (iii) Extension are respectively
In a non leap year the probability of getting 53 Sundays or 53 Tuesdays or 53 Thursdays
In a normal embryosac, the ploidy level of egg cell, polar nuclei, synergids and secondary nucleus is
In a p-n junction diode, the increase in forward voltage of 0.19 V increases the forward current by 37.6 mA. The dynamic resistance of the junction is
In a leap year the probability of having 53 Sundays or 53 Mondays is
In a mature dicot stem which has undergone secondary growth, youngest layer of secondary xylem is situated
In a hexagonal close packed structure (hcp) of spheres, the fraction of the volume occupied by the sphere is A. In a cubic close packed structure, the fraction is B. The relation for A and B is
In a hydrogen atom, the radius of $n^{th}$ Bohr orbit is $r_n$. The graph between $log(r_n/r_1)$ and $logn$ will be
In a hydrogen atom the total energy of electron is
In a group of students, mean weight of boys is 80 kg and mean weight of girls is 50 kg. If the mean weight of all the students taken together is 60 kg, then the ratio of the number of boys so that of girls is
In a head an elastic collision of a very heavy body moving at $v$ with a light body at rest, velocity of the heavy body after collision is
In a healthy adult man, the smallest type of leucocytes are
In a group of 52 persons, 16 drink tea but not coffee, while 33 drink tea. How many persons drink coffee but not tea ?
In a gas equation, PV= RT V refers to the volume of
In a Geiger-Marsden experiment. Find the distance of closest approach to the nucleus of a $7.7 \,MeV$ $\alpha$-particle before it comes momentarily to rest and reverses its direction. ($Z$ for gold nucleus $= 79$)
In a geometric progression consisting of positive terms, each term equals the sum of the next two terms. Then common ratio of the G.P. is
In a frequency distribution, the mid value of a class is 10 and the width of the class is 6. The lower limit of the class is
In a factory which manufactures bolts, machines $A$, $B$ and $C$ manufacture respectively $25\%$, $35\%$ and $40\%$ of the bolts. Of their output $5\%$, $4\%$ and $2\%$ are respectively defective bolts. $A$ bolt is drawn at random from the total production and is found to be defective. Find the probability that it is manufactured by machine $B$.
In a football championship, $153$ matches were played. Every team played one match with each other, the number of teams participating in the championship is
In a double slit experiment, the distance between the slits is $d$. The screen is at a distance $D$ from the slits. If a bright fringe is formed opposite to one of the slits, its order is