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Which of the following graphs is correct for a particle moving in a circle of radius $$r$$ at a speed of $$v$$ where $$a$$ is the magnitude of acceleration?
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Which of the following graphs is correct for a particle moving in a circle of radius $$r$$ at a speed of $$v$$ where $$a$$ is the magnitude of acceleration?
Electronic configuration of $$\mathrm{Na^+}$$ is $$(2,8)$$ and that of sodium element is $$(2,8,1)$$. Choose the correct statements.
i. $$\mathrm{Na^+}_{(g)}$$ is more stable than $$\mathrm{Na}_{(g)}$$.
ii. $$\mathrm{Na^+}_{(g)}$$ is less stable than $$\mathrm{Na}_{(g)}$$.
iii. $$\mathrm{Na^+}_{(aq)}$$ is more stable than $$\mathrm{Na}_{(aq)}$$.
iv. $$\mathrm{Na^+}_{(aq)}$$ is less stable than $$\mathrm{Na}_{(aq)}$$.
What will be the remainder if the number $$7^{2015}$$ is divided by $$25$$?
In humans, the digestion of carbohydrates happens or takes place in the following parts of the digestive system.
Light travels from medium X to medium Y as shown in the adjacent figure.
Hess$$'$$Law states that the heat evolved or absorbed in a chemical reaction is the same whether the process takes place in one or in several steps.
Heat evolved in the combustion of one mole $$\mathrm{C(s)}$$ in excess oxygen is $$x\,\mathrm{kJ/mol}$$, and that for the combustion of $$\mathrm{H_2(g)}$$ is $$y\,\mathrm{kJ/mol}$$ and for that of $$\mathrm{C_6H_6(l)}$$ is $$z\,\mathrm{kJ/mol}$$. Therefore, the heat change involved in the formation of one mole of $$\mathrm{C_6H_6(l)}$$ from the given equation is
If $$A(p,q+r)$$, $$B(q,r+p)$$ and $$C(r,p+q)$$ are points then area of triangle $$ABC$$
Photosynthesis in plants is carried out in
A particle moves along the x-axis according to the equation $$x=6t^2$$ where $$x$$ is displacement in meters and $$t$$ is time in seconds. Therefore
What occurs when $$\mathrm{H_2O(l)}$$ evaporates?
(i) Covalent bonds are broken.
(ii) Only dipole-dipole forces are overcome.
(iii) Heat is absorbed by water from the surroundings.
(iv) It becomes oxygen and hydrogen gas.
Evaluate $$\frac{3}{4}+\frac{3}{28}+\frac{3}{70}+\frac{3}{130}+\cdots+\frac{3}{9700}$$.
The following technique can be used for deciphering the arrangement of nucleotides in genes.
The "reaction" force does not cancel the "action" force because
Which of the following Lewis dot structures best describes the structure of peroxide ion of sodium peroxide?
What is the sum of all three digit even numbers divisible by seventeen?
When a red blood cell was placed in an animal cell in 3 different solutions, the following morphological observations were made under a microscope.
The above three solutions can be classified in the order of
A stone is thrown horizontally and follows the XYZ path as shown in the adjacent figure. The direction of the acceleration of the stone at point Y is
Ionization Energy is defined as the energy required for removing the most loosely bound electron from an isolated gaseous atom or ion.
and so on..
Identify element A.
The adjacent sides of a parallelogram are $$30\,\mathrm{cm}$$ and $$20\,\mathrm{cm}$$. The length of one diagonal is $$40\,\mathrm{cm}$$. What is the length of the other diagonal?
Genetic material DNA in plants occurs in which of the following cell organelles?
The diagram shows total internal reflection. Which of the following statement is not true?
A chemist$$'$$s report on a batch of pharmaceutical products, Aspirin $$\mathrm{C_9H_8O_4}$$ of $$250\,\mathrm{mg}$$ and Paracetamol $$\mathrm{C_8H_9NO_2}$$ of $$500\,\mathrm{mg}$$ indicated a $$+0.5\%$$ weight error in each tablet. Due to this error, the consumer gets extra $$x$$ molecules of aspirin per tablet and extra $$y$$ molecules of paracetamol per tablet. Choose the best relation between $$x$$ and $$y$$.
The value $$41^{16}-14^{16}$$ is a multiple of
The equation given below represents the process of photosynthesis.
[image]
Identify (i) and (ii).
The centre of gravity of a body coincides with the center of mass
Sodium reacts with excess oxygen to form sodium oxide. A student wants to prepare $$1.24\,\mathrm{g}$$ of sodium oxide. While doing the calculations, he uses atomic number of sodium instead of atomic mass. What is the approximate percentage error in the mass of sodium oxide obtained due to this mistake?
What will be the remainder if the number $$(1000000)^3$$ is divided by $$143$$?
Which of the following sequence depicts the flow of blood in human circulatory system?
A body is in equilibrium under the combined action of several forces then
From the following pool of molecules
How many isomers are represented above
How many four digit numbers divisible by twenty nine have the sum of their digits 29?
Choose the right combination of heart types and animals.
A photo frame can be hung on the wall with string in three different ways as shown in the adjacent figure below. The tension in the string is
Ionic radii of following species are
How many triangles are there in this figure?
Raju Sharma, a 10th standard student participated in 100 meter sprint. During running he developed painful muscle contraction and fell down. The physical education teacher rushed to him and gave a hot water massage. Raju Sharma slowly recovered from the cramp. Identify the right explanation.
If a force acting is conservative only when
Sati was studying neutralisation reaction. She accidentally dropped $$x$$ grams of a sodium carbonate monohydrate into a $$100\,\mathrm{mL}$$ solution of $$\mathrm{HCl}$$ whose concentration was $$0.25\,\mathrm{M}$$. $$10\,\mathrm{mL}$$ from this final solution was taken and titrated against $$0.05\,\mathrm{M}$$ $$\mathrm{NaOH}$$ solution to yield a titre value of $$20\,\mathrm{mL}$$. What is the value of $$x$$.
$$8888888 $$ x $$8888888$$ is a fifteen digit number divisible by $$22$$. Find the eighth digit in the number.
The various parts of the human respiratory system are given below.
(i) Nasal passage (ii) Pharynx (iii) Wind pipe
(iv) Bronchus (v) Bronchioles (vi) Alveoli.
Identify the right sequence of air passage during exhalation.
A lift is moving up at constant speed. Consider the following statements.
I. The tension in the string is constant.
II. The K.E of the elevator is constant.
III. The gravitational P.E of the earth lift system is constant.
IV. The acceleration of the elevator is zero.
V. The mechanical energy of the earth lift system is constant.
Choose the correct option.
Amongst the sixteen ✔ and ✗ marks, how many cases are incorrect?
✔ means displacement reaction occurs
✗ means no displacement reaction occurs.
In the adjoining figure segment AD, BE and CF are the altitudes of triangle ABC. Find $$AD\times BC$$ if $$AB\times AC=409.6$$ and $$BE\times CF=202.5$$.
The testes of men lie in a small muscular pouch called scrotum located outside the abdominal cavity. Choose the correct reason.
Two toy cars a and b fixed with spring at front collide as shown in the figure below. Car a has a mass of $$200\,\mathrm{g}$$ and is initially moving to the right. Car b has a mass of $$300\,\mathrm{g}$$ and is initially at rest. When the separation between the cars is minimum,
What is the ratio of number of electrons gained by acidified $$\mathrm{KMnO_4}$$ and acidified $$\mathrm{K_2Cr_2O_7}$$ in the reaction given below
If $$\sqrt{338}-\sqrt{288}=m$$ then $$m=$$?
Which of the following is NOT produced by microbial activity?
A concave spherical mirror has a focal length of $$12\,\mathrm{cm}$$. If an object is placed $$6\,\mathrm{cm}$$ in front of it, the position of the image is
Methylcyclobutane is a saturated alkane. What is its molecular formula?
$$5901AB04$$ is an eight digit number divisible by $$792$$. Find $$A+B$$.
Among the following, which is not true about vaccines?
The current $$I$$ in the branch shown in the adjacent figure is
A closed circuit shown in the adjacent figure includes a resistor of resistance $$20.0\,\Omega$$ and battery of emf $$3.0\,\mathrm{V}$$ and internal resistance of $$1\,\Omega$$. The internal resistance of the battery can be considered in series with it. The voltage drop across the resistor of resistance $$20\,\Omega$$ is
A circuit which is used for charging a battery is shown in the adjacent figure. The battery B has emf $$6\,\mathrm{V}$$ and internal resistance of $$2\,\Omega$$. The charging battery A has an emf of $$9\,\mathrm{V}$$ and internal resistance of $$1\,\Omega$$. The voltage across the points P and Q
The circuit shown in adjacent figure consists of an external resistance of $$10.0\,\Omega$$ connected across two batteries of emfs $$6.0\,\mathrm{V}$$ and $$9.0\,\mathrm{V}$$ with internal resistance of $$1.0\,\Omega$$ each. Find the power dissipated by the $$10.0\,\Omega$$ resistor.
Choose the correct sets which represent the oxides as acidic, basic, neutral, amphoteric respectively.
(i) $$\mathrm{CO_2}$$, $$\mathrm{MgO}$$, $$\mathrm{N_2O}$$, $$\mathrm{H_2O}$$
(ii) $$\mathrm{SO_2}$$, $$\mathrm{NO}$$, $$\mathrm{CO}$$, $$\mathrm{Al_2O_3}$$
(iii) $$\mathrm{P_2O_5}$$, $$\mathrm{ZnO}$$, $$\mathrm{NO}$$, $$\mathrm{Al_2O_3}$$
(iv) $$\mathrm{SO_3}$$, $$\mathrm{CaO}$$, $$\mathrm{N_2O}$$, $$\mathrm{PbO}$$
What is the smallest natural number when multiplied by $$15$$ and divided by $$63$$ gives remainder $$21$$?
Gram positive bacteria will have one of the specific characters. Identify it.
A silver article turns black when kept open in air for few days. The article when rubbed with toothpaste again starts shining because
The sum of first four terms of an A.P is 56. The sum of last four terms of same A.P is 112. The first term of the A.P is 11. Find the number of terms in that A.P.
Mitochondrial equivalent in prokaryotic bacterial cell is
A compound A when treated with a dilute mineral acid gives a gas which when passed through a solution of B regenerates A. Further, a gas C that is obtained from the addition of concentrated $$\mathrm{HCl}$$ to $$\mathrm{KMnO_4}$$ crystals is used to react with B to give D. Identify A, B, C and D.
If $$a$$ : $$b$$ =$$c$$ : $$d$$ then how many of the following statements are true?
(i) $$c(a+b)=a(c+d)$$
(ii) $$d(a-b)=b(c-d)$$
(iii) $$(a^2+b^2)(ac-bd)=(a^2-b^2)(ac+bd)$$
(iv) $$\frac{a^2}{b^2}+\frac{c^2}{d^2}=\frac{2ac}{bd}$$
Endemic species refers to
$$5\,\mathrm{g}$$ of a gas at $$27^\circ\mathrm{C}$$ occupied the same volume as $$0.250\,\mathrm{g}$$ of dihydrogen at $$17^\circ\mathrm{C}$$ at the same pressure. Find out molecular weight of the gas.
Select any three distinct digits. Form a three digit number. Form another number by reversing the digits. Find the difference of these two numbers. What is the G.C.D of all such differences?
Which of the following option is not true about the viruses?
The coefficient of linear thermal expansion of steel is $$11\times10^{-6}\,{}^\circ\mathrm{C}^{-1}$$. The percentage change in the length of the rod when temperature changes by $$70^\circ\mathrm{C}$$ is
An acid-base titration is a technique where a solution of known concentration of acid/base is used to determine the concentration of an unknown solution of acid/base. These titrations typically use a pH indicator solution to denote the end point of the reaction. A pH indicator is a compound added in small quantities toa solution to indicate the pH visually(generally by appearance/disappearanceor change in colour). A typical procedureis as follows: A certain volume ‘V1’ of unknown concentration ‘M1’ of HCl istaken in a conical flask, to which a few drops of phenolphthalein indicatorsolution is added. The solution remainscolourless. From a burette (a graduateddropper) a solution of NaOH, whoseconcentration is known, ‘M2’, is addeddropwise into the conical flask until a palepink colour is obtained and is termed as the end point. The amount of solution dispensedfrom the burette to obtain the end point is noted as ‘V2’. Phenolphthalein indicator change sits colour to pink only when the pH of the solution is above 9.5. Similarly, another indicator,methyl orange, is red in colour below pH 3.7 and yellow above. Given below is a graph of pHof the solution in the conical flask and the reading of the burette in the course of the titration. The equivalent point is theoretically defined as the point in the graph where the number of moles HCl in the conical flask becomes equal to the number of moles of NaOH run down the burette. Note the difference between end point and equivalence point.
Which is the correct graph that represents the titration of NH4OH (from burette) with HCl?
There are ten numbers in a certain A.P. The sum of first three terms is 321. The sum of last three numbers is 405. Find the sum of all the ten numbers.
Regeneration in animal kingdom is observed in which of the following animals?
A cube of side $$4\,\mathrm{cm}$$ made of wood is floating in water of density $$1.00\,\mathrm{g\,cm^{-3}}$$. When a small steel ball is embedded in the cube it just immerses in water. If density of wood is $$0.76\,\mathrm{g\,cm^{-3}}$$, then mass of the steel ball is
Given below is the pH versus volume curve for titration of $$\mathrm{Na_2CO_3}$$ in the conical flask with $$\mathrm{HCl}$$.
Choose the correct statement based on the above graph.
How many three digit numbers are divisible by $$13$$ and having middle digit 5?
In biology, Polymerase Chain Reaction PCR refers to which of the following option?
A swing playing with small amplitude can be considered as a simple pendulum. Such a swing is set to oscillate with an amplitude $$a$$ and frequency $$f$$. When it is at its mean position, a box of same mass as that of the seat of the swing is dropped on it and it starts moving with the swing. Choose the correct statement.
The pH of the $$10^{-8}\,\mathrm{M}$$ $$\mathrm{HCl}$$ solution is
Two parallel chords $$96\,\mathrm{cm}$$ and $$28\,\mathrm{cm}$$ long are on the opposite side of the centre of the circle with radius $$50\,\mathrm{cm}$$. Find the area of the quadrilateral whose vertices are the end points of the chords.
Each chromosome contains
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