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Cryopreservation, in vitro fertilisation, micropropagation/tissue culture sperm bank/seed bank/gene bank.

तरंग-संचरण की दिशा को।

(c)    कीटोन

Correct option is B) translatory motion
 

When the bob of the pendulum is released after taking it slightly to one side, it begins to move to and fro. The to and fro motion of a simple pendulum is an example of periodic or an oscillatory motion.

Time taken to complete 20 oscillations = 32 s

Time taken to complete 1 oscillation = 32/20 s = 1.6 s

The time period of a pendulum is the time taken by it to complete 1 oscillation.

The time period of the pendulum is 1.6 seconds.

Distance = 240 km

Time is taken = 4 hours

Speed = Distance covered/Time taken = 240 km / 4 h

= 60 km/h

Speed of train = 60 km/h

Time is taken = 15 min

Speed = 2 m/min

Distance = speed x time = 2 x 15 = 30m

The distance between Salma’s school and her house is 30 m.

Odometer : An odometer is an instrument used for measuring the distance traveled by a vehicle.

The correct option is B) Distance travelled by the vehicle.

The correct option is C) Speedometer.

The answer is C) Speedometer 

Distance = 57336.0 km – 57321.0 km = 15 km

Speed in km / min

15 km/20 km = 3/4 km/min

Speed in km/hr

=\(\frac{15 \,km}{\frac{1}{3}h}\) = (15 x 3)km/h = 45 km/h.

Dust particles are at rest with respect to the carpet. When the carpet is beaten, the dust due to inertia tends to remain at rest while the carpet moves due to external force applied. So, the dust comes out of the carpet. Inertia of motion is not involved here as the dust particles are at rest and inertia is involved in this case. So, option B. & C. are not the correct option.

Luggage is in contact with the roof of the bus. When the bus is moving the luggage is also in the state of motion and had a tendency to remain in motion due to law of inertia. When the driver apply the brakes, the bus stops suddenly but the luggage is in motion and thus fall from the roof. It is therefore advised to tie the luggage.

An athlete runs before jumping to gain momentum because it helps in jumping higher and longer because of inertia of motion gained due to the motion. When the athletes jump, they already have a forward motion that would be greater than that of a jump made from standing in one spot. While running, the athlete cannot gain energy or apply larger force because initially he would be rest and while running, he will lose energy.

Newton’s second law states that the rate of change of momentum of a body is directly proportional to the force applied, and this change in momentum takes place in the direction of the applied force. First law gives measure of inertia.

According to Newton’s third law, to every action there is equal and opposite reaction. But these two forces are acting on two different objects and not on the same object. If the forces act on same object the forces will get cancelled and the object will not move.

Force ∝  acceleration. Acceleration is rate of change of velocity. Mass is a constant quantity. Inertia is a tendency to resist the state of rest or motion.

The property or tendency of a moving object to continue moving is called momentum. For an object moving in a line, the momentum is the mass of the object multiplied by its velocity. Volume, density and shape does not determine the momentum.

False

According to Newton’s third law, to every action there is equal and opposite reaction. But these two forces are acting on two different objects and not on the same object. If the forces act on same object the forces will get cancelled and the object will not move.

True

A balanced force does not produce any motion but unbalanced force does.

False

Impulse = force × time = change in momentum

Rate of change of momentum is force applied and not momentum.

False

One Newton is the force required to accelerate one kilogram of mass at the rate of one meter per Second Square in the direction of the applied force.

Zero unbalanced force means the body is not accelerating but it moves with a constant velocity.

Balanced forces acts on an object in opposite directions and are equal in strength. They do not cause a change in the speed of a moving object. For all the other options unbalanced forces are required.

The correct answer is b) reduce the force exerted by the ball

Nitric acid oxidises iron(II) sulphate to iron (III) sulphate with the liberation of nitric oxide gas. 

6FeSO₄ +3H₂SO₄ + 2HNO₃ (dil. ) → 3Fe₂ (SO₄ )₃ + 4H₂O +2NO 

The nitric oxide so formed reacts wtih more of iron(II) sulphate to form nitrosoferrous sulphate, which appears in the form of brown ring at the junction of liquids. 

FeSO₄ + NO → FeSO₄ .NO 

(1) FeSO₄ .NO

(2) X-FeSO₄       Z-H₂SO₄

(3) When test tube is disturbed, cone. H₂SO₄ mixes with water (in Fe₂SO₄ solution). Dilution of cone. H₂SO₄ with water is an exothermic process. The heat so produced assists in the decomposition of unstable brown ring.

(4)Cone. H₂SO₄ ), (density 1.98) is twice as heavy as water (density : 1). As such cone. H₂SO₄ settles down and iron(II) sulphate layer remains alone it resulting in the formation of brown ring at the junction.

(5) Nitric oxide (NO).

According to Newton’s law, an object which is at rest or in motion will continue its state of rest or motion unless and until an external force is applied on it. This property is known as inertia. Dust particles are at rest with respect to the carpet. When the carpet is beaten, the dust due to inertia tends to remain at rest while the carpet moves due to external force applied. So, the dust comes out of the carpet.

A) static inertia of dust

Number of diagonals = ⁿC₂ – n = 170.

\(\frac{n(n - 1)}{2} - n = 170\)

n² – n – 2n = 340 

⇒ x² – 3x – 340 

(n + 17) = 0 

n = 20 or -17 

∵ n can’t be negative n = 20

We have to select 6 marbles out of 10 and 4 white out of 6 white marbles = ¹⁰C₆ × ⁶C₄ = 210 × 15 = 3,150.

One particular person is included, we have to choose from 9, this can be done in ⁹C₃ ways.

There are as many codes as there are ways of filling 4 vacant places in succession by the first 10 letters of the English alphabet, keeping in mind that the repetition of letters is not allowed.

The first place can be filled in 10 different ways by any of the first 10 letters of the English alphabet following which, the second place can be filled in by any of the remaining letters in 9 different ways. The third place can be filled in by any of the remaining 8 letters in 8 different ways and the fourth place can be filled in by any of the remaining 7 letters in 7 different ways.

Therefore, by multiplication principle, the required numbers of ways in which 4 vacant places can be filled is 10 × 9 × 8 × 7 = 5040 

Hence, 5040 four-letter codes can be formed using the first 10 letters of the English alphabet, if no letter is repeated.

It is given that 2 questions are compulsory out of 5 questions.

So, the other 2 questions can be selected from the remaining 3 questions in ³C₂ = 3 ways.

Six boys can arranged in a circle in (6 – 1)! = 5!, 6 girls can permute in 6! Ways. 

∴ The number of ways is 6! × 5!.

4 students out of 10 and 2 lecturers out of 8 can be selected in ¹⁰C₄ × ⁸C₂, ways = 210 × 28 = 5,880

¹⁰C₅ ways = 252 ways,

Since there is no condition for positive (+) sign, fix them in a row. 

+++++++ 

There are 6 places in between each plus and one before and one before and one after these positive (+) sign. 

i.e., these are 8 places for negative (-) sign and 5(-) negative signs are there. 

∴ These negative (-) signs can be placed in ⁸C₅ ways. 

= ⁸C₅ 

= \(\frac{8!}{3!\space5!}\)

= \(\frac{8.7.6}{3.2.1} = 56\)

True

24 selections containing at least

one red ball out of a bag containing 4 red and 5 black balls.

= 5x5

= 25

Case 1: Both join 

In case both the students decide to join, 

¹³C₈ × ²C₂ ways = ¹³C₈ = \(\frac{13!}{8!\space5!}=1287\) 

Case 2: In case none of them join, 

it will be ¹³C₁₀ Ways 13C₁₀ = \(\frac{13!}{3!\space10!}=286\)

Total number of cases are = ¹³C₈ + ¹³C₁₀ 

1287 + 286 = 1573

False

Select 3 candidate out of 5=⁵C₃

Select 9 candidate out of 22=²²C₉

The number of ways in which the selection can be made is⁵C₃ × ²⁰C_9.

Two cases are possible: 

(i) Selecting 4 out of first five questions and 6 out of remaining 8 questions 

∴ Number of choices in this case = ⁵C₄ × ⁸C₆ = ⁵C₁ × ⁸C₂ = \(\frac{5\times8\times7}{1\times2}=140\) 

(ii) Selecting 5 out of first five questions and 5 out of remaining 8 questions. 

⇒ Number of choices = ⁵C₅ × ⁸C₅ = 1 × ⁸C₃ = \(\frac{5\times8\times7}{1\times2\times3}=56.\) 

∴ Total number of choices = 140 + 56 = 196.

Combination from A and from B ∷ \(\frac{4}{5};\frac{5}{5};\frac{6}{4}\)

Number of way to get \(\frac{4}{6}\) pattern = ⁶C₄ × ⁷C₆ 

= \(\frac{6!}{2!\space4!}\times\frac{7!}{1!\space6!}\) 

= \(\frac{6.5}{2.1}\times\frac{7}{1}\) 

= 15 × 7 = 105 

Number of ways to get \(\frac{5}{5}\)pattern = ⁶C₅ × ⁷C₅ 

= \(\frac{6!}{1!\space5!}\times\frac{7!}{2!\space5!}\) 

= \(\frac{6}{1}\times\frac{7\times6}{2\times1}\) 

= 6 × 21 = 126 

Number of ways to get the 6 4 pattern = ⁶C₆ × ⁷C₄ 

= \(\frac{6!}{0!\space 6!}\times\frac{7!}{3!\space4!}\) 

= \(1\times\frac{7.6.5}{3.2.1}\)

= 35 

Hence, total number of ways= 105 + 126 + 35 

= 266

False

⁶C₂x⁶C₅+⁶C₃x⁶C₄+⁶C₄x⁶C₃+⁶C₅x⁶C₂ = 780

Total = 420 ways

The number of six-digit numbers, all digits of which are odd is 5⁶.

Number of digit=10

Number of odd digit=5

number of six-digit numbers= 5⁶

Total number of digits = 0,1,2,2,3 

Total number formed by these digit = \(\frac{5!}{2!}=\frac{120}{20}=60\) 

Total number formed by starting 0 = \(\frac{4!}{2!}=\frac{24}{2}=12\)

Total number formed by starting 1 = \(\frac{4!}{2!}=\frac{24}{2}=12\)

Total number formed greater than 2000 

= 60 − 12 − 12 

= 36