Explore topic-wise InterviewSolutions in Current Affairs.

This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.

1.

The Nobel Prize 2018 in Physiology or Medicine was won byA. Yoshinori OhsumiB. Kazuo IshiguroC. James P. Allision and Tasuku HonjoD. William D.Northaus and Paul M. Romer

Answer» Correct Answer - C
2.

The paris agreements of the United Nations Framework Convention on Climate Change is to limit global warming well belowA. `1.0^(@)C`B. `1.5^(@)C`C. `2.0^(@)C`D. `2.5^(@)C`

Answer» Correct Answer - C
3.

Define Anaphylaxis.

Answer»

Anaphylaxis is the classical immediate hypersensitivity reaction. It is a sudden, systematic, severe and immediate hypersensitivity reaction occurring as a result of rapid generalized mast-cell degranulation

4.

Tiya said, ”Shut the door.” – to open the door.According to you, did he give the correct command?(a) True(b) False

Answer»

Correct answer is (b) False

5.

James P. Allison and Tasuku Honjo won the Nobel Prize-2018 in the filed of Physiology or Medicine for their discovery ofA. molecular mechanisms controlling the circadian rhythmB. cancer therapy by inhibition of negative immune regulationC. mechanisms for autophagyD. novel therapy against malaria

Answer» Correct Answer - B
6.

State any two unique features of ELISA test.

Answer»

ELISA is highly sensitive and can detect antigen even in nanograms.

ELISA test does not require radioisotopes or radiation counting apparatus.

7.

What is the child careful about according to the poem?

Answer»

The child is careful about not tripping others.

8.

Read the poem below and choose the word that is not an action word:-a) hopb) spinc) floord) roll

Answer»

Correct answer is (c) floor

9.

Choose the correct statement:-1. The child in the poem is careless2. The child in the poem is careful.

Answer»

Correct statement is  2. The child in the poem is careful

10.

Spread of cancerous cells to distant sites is termed as _________. (a) Metastasis (b) Oncogenes (c) Proto-oncogenes (d) Malignant neoplasm

Answer»

Spread of cancerous cells to distant sites is termed as Metastasis.

11.

Name the active chemical found in the medicinal plan Rauwolfia vomitoria. What type of diversity does it belongs to?

Answer»

Rauwolfia vomitoria can be cited as an example for genetic diversity. Reserpine is an active chemical extracted from Rauwolfia vomitoria.

12.

Read and recite the poem with action. Here  in the poem, legs are for a. clappingb. snapc. jumpingd. see

Answer»

Correct option is C. jumping

13.

Assertion (A): Streptomycin is an antibiotic. Reason (R): Antibiotic are microbial chemicals inhibits the growth of pathogenic microbe.(a) A is right R is wrong(b) R explains A (c) A and R are wrong (d) A is wrong but R is right

Answer»

(b) R explains A

14.

Match the body parts names with their action.List AList B1. handsa) jumping2. fingersb) see3. legsc) snap4. eyesd) clapping

Answer»

1. d

2. c

3. a

4. b

15.

Write whether the given statement is True or False .My eyes help me to see.(a) True(b) False

Answer»

Correct answer is (a) True

16.

Write whether the given sentence is True or False. A pencil is used to write. (a) True(b) False

Answer»

Correct answer is True

17.

Match the picture with its name List AList Ba) pencilb) flowerc) cupd) book

Answer»

1.d

2.c

3.a

4.b

18.

Look at the pictures carefully and fill in the blanks with the correct preposition- in, on, under-1. The dog is ......... the kennel.2. The bird is ............. the roof of the kennel.

Answer»

1. In

2. on

19.

\( \sin ^{-1} x+\sin ^{-1} 2 x=\frac{\pi}{3} \)

Answer»

sin-1 x +  sin-1 2x = \(\frac{π}{3}\)

sin-1 ( x\((x { \sqrt{1-4x^2} \ } + 2x { \sqrt{1-x^2} \ }) =\frac{π}{3}\)

( ∵ sin-1 x  + sin-1 y = sin-1 \((2x { \ \sqrt{1-y2} \ }+{ 4 \sqrt{1-x^2} \ }))\)\(\)

⇒ \(x { \sqrt{1-4x^2} \ } +2x { \sqrt{1-x^2} \ } =sin\frac{π}{3}=\frac{√3}{2}\)

⇒ x2 (1- 4x2) + 4 x2 (1-x2) + 4x2 \( { \ \sqrt{(1-4x^2)(1-x^2)} \ }=\frac{3}{4}\)

(by squaring on both sides)

⇒ 16x\( { \ \sqrt{(1-x^2)(1-4x^2)} }=3-(x^2 -4x^4+4x^2-4x^4)\)

⇒ \(16x^2 = { \sqrt{(1-x^2)(1-4x^2)} \ } =3-5x^2+8x^4\)

⇒ 256x(1 - x2) (1- 4x2)  = 9 + 25x4+ 64x8 - 30 x2 + 48 x- 80x6

⇒ 256x(1 - 5x+4x) = 64x8 - 80x6 + 73x4 - 30 x2 + 9

⇒ 256x- 1280x + 1024 x = 64 x8 - 80 x6 + 73x4 - 30x2 +9

⇒ 960x8 - 1200x6 + 183x4 +30x2 - 9 = 0

20.

Which of the following statement is/are correct?1. The directorate of mines and minerals is located in Jaipur.2. Rajasthan is the largest producer of copper in India.3. Rajasthan is endowed with the largest lead-zinc ore deposit.1. 1 and  2 only2. 2 and 3 only3. 3 only4. All the above

Answer» Correct Answer - Option 3 : 3 only

The correct answer is 3 only.

  • Department of Mines and Geology (DMG) of Rajasthan State, headquartered at Udaipur.
  • Madhya Pradesh is the largest producer of copper in India.
  • Rajasthan is the second-largest producer of copper.
  • Rajasthan is endowed with the largest lead-zinc ore deposit.
  • Hence the only 3rd statement is correct.

  • Copper:
    • Madhya Pradesh is the largest producer of copper
    • Rajasthan is the second-largest producer of copper
    • Khetri mines are the largest producing site at Ganeshwar.
      • Ganeshwar is located near the Sikar-Jhunjhunu area of the Khetri copper belt in Rajasthan.
    • Copper has wide application and uses in electrical wiring due to its high conductivity and ductility
    • Copper ore is called chalcopyrite.
  • Lead-zinc ore:
    • ​Lead and zinc have the largest deposit in Rajasthan.
    • Rampura-Agucha is a place of ore deposits in the Bhilwara district of Rajasthan.
    • Production by Hindustan zinc limited.
    • Lead has wide use and application in batteries, electronics, and medical devices. 
21.

In which state are the Khetri mines located?1. Orisha2. Rajasthan3. Bihar4. Uttar Pradesh

Answer» Correct Answer - Option 2 : Rajasthan

The correct answer is Rajasthan.

  • The Khetri mines are located in Rajasthan.
    • Khetri mines in Rajput are famous for copper mines.
    •  Khetri Nagar, which is located 10 km far from Khetri, is known as the 'Tamba Project'.
    • Khetri Nagar was built by Hindustan Copper Limited which is a public sector under the "Government of India" and under his jurisdiction.
    • Khetri Nagar is a town in the Jhunjhunu district of Rajasthan in India.
    • Khetri Nagar is also very well known with the name of 'Copper'.

  • There are four main mining methods: underground, open surface (pit), placer, and in-situ mining.
    • Underground mines are more expensive and are often used to reach deeper deposits.
    • Surface mines are typically used for more shallow and less valuable deposits.
    • Placer mining is used to sift out valuable metals from sediments in river channels, beach sands, or other environments.
    • In-situ mining, which is primarily used in mining uranium, involves dissolving the mineral resource in place then processing it at the surface without moving rock from the ground.
22.

Which of the following, a major film actor, has been selected for the prestigious award in France called 'Knight of the Order of Arts and Letters'.1. Kamal Hassan2. Shabana Azmi3. Rajinikanth4. Anupam Kher

Answer» Correct Answer - Option 1 : Kamal Hassan

The correct answer is Kamal Hassan.

  • Kamal Hassan had won the Henri Langlois Award for his contribution to cinema in France as a child artist in his debut movie Kalathoor Kannamma in 1959.
  • In 2016, He was awarded the Knight Of the Order of Arts and Letters for his huge contribution to cinema.

  • Bollywood artists who were honoured by foreign countries for their contribution to cinema:
Satyajit Ray
  • He was conferred France’s highest civilian award the ‘Legion of Honour’ at a function at the Calcutta Library in 1989.
Amitabh Bachchan
  • He was conferred France’s highest civilian award the 'Legion of Honour'.
  • He was also decorated with the Medal of Honour of Morocco by Morocco’s King Mohammed.
Anurag Kashyap
  • The Gangs Of Wasseypur director had been conferred with the Knight of the Order of Arts and Letters, a prestigious award from the French Government in 2015.
Aishwarya Rai Bachchan
  • In 2011, she was conferred with the Knight of the Order of Arts and Letters by the Ambassador of France in New Delhi, Jerome Bonnafont.
Shah Rukh Khan
  • He was conferred with the Knight of Legion of Honor in 2014.
  • In 2012, he was conferred with Morroco’s Medal of Honor at the Marrakech International Film Festival.
Sajid Nadiadwala
  • In 2016, producer Sajid Nadiadwala was decorated with the Knight of the Order of Arts and Letters by Mr Alexandre Ziegler, Ambassador of France to India.
Manish Arora
  • The first Indian designer to be conferred with the Legion of Honour in 2016.
Nandita Das
  • Critically acclaimed actor-director Nandita Das was conferred with the Knight of the Order of Arts and Letters by Jerome Bonnafont during her felicitation in Delhi.
Kalki Koechlin
  • She conferred “Knight of the Order of Arts and Letters” in 2018.
Sanjna Kapoor
  • She was awarded the French honour of Chevalier dans l’Ordre des Arts et des Lettres’ (Knight of the Order of Arts and Letters) for her outstanding contribution to theatre in 2020.
23.

In which state is the Singareni Mines located?1. Odisha2. Telangana3. Maharashtra4. Chhattisgarh

Answer» Correct Answer - Option 2 : Telangana

The correct answer is Telangana.

  • The Singareni coal reserves stretch across 350 Km of the Pranahita located in Godavari Valley of Telangana.
  • Singareni Collieries Company Limited (SCCL) is currently operating 18 opencast and 27 underground mines in 4 districts of Telangana.
  • The present Company was incorporated on 23rd December 1920.

  • Important mines in Odisha:
    • Iron ore in Joda, Keonjhar, Jajpur.
    • Manganese in Keonjhar, Rayagada, Sundergarh.
    • Bauxite in Balangir, Koraput, Kalahandi, Sambalpur.
    • Coal in Jharsuguda, Talcher.
  • The principal mineral-bearing belts in Maharashtra are the Vidarbha area in the east and the Konkan area in the west.
    • Important mineral occurrences are:
      • Bauxite in Kolhapur, Raigad, Ratnagiri, Satara, Sindhudurg, Thane districts.
      • China clay in Amravati, Bhandara, Chandrapur, Nagpur, Sindhudurg, Thane districts.
      • Chromite in Bhandara, Chandrapur, Nagpur, Sindhudurg districts.
      • Coal in Nagpur, Chandrapur, Yavatmal districts.
      • Dolomite in Chandrapur, Nagpur, Yavatmal districts.
      • Gold in Bhandara, Nagpur districts.
  • Important mines in Chhattisgarh:
    • Iron ore in Bailadila, Raoghat, Hahaladdi/Kodapakha, Metabodeli, Dalli Rajhara.
    • Bauxite in Mainpat, Kandraja block, Jamirapat, Pendrapat.
    • Coal in Sohagpur, Jhilimili, Chirimiri, Bisrampur, Lakhanpur, Panch Bhahni, Korba, Mand Raigarh.
24.

Apart from Virat Kohli, who is the only other member of the 2008 Under 19 World Cup winning squad to have played a test match for India?

Answer»

Abhinav Mukund

25.

प्रत्येक रविवार का जिन 3 मील जॉगिंग करता है। यदि सोमवार को वह 1 मील जॉगिंग करता है और सप्ताह के शेष दिनों में वह प्रत्येक दिन पिछले दिन की अपेक्षा 1 मील अधिक जॉगिंग करता है। बताइए 2 सप्ताह में जिन कितने मील की जॉगिंग करता है?A. 42B. 63C. 48D. 98

Answer» Correct Answer - C
`((S, M, T, W, T, F, S),(3,1 , 2, 3, 4, 5, 6))`
Jogs in one weak `=24`
Total Jogs in two week
`=24xx2`
`=48`
26.

एक व्यक्ति जिसकी लम्बाई 169 सेमी है, एक खम्भे के सहारे खड़ा हुआ है। उसकी छाया की लम्बाई 130 सेमी है। तो उस खम्भे की लम्बाई ज्ञात करें, जिसकी छाया की लम्बाई 420 सेमी है?A. 550 cmB. 589 cmC. 323 cmD. 546 cm

Answer» Correct Answer - D
यदि छाया 130 cm है तो वास्तविक लम्बाई 169 cm है।
यदि छाया `1cm` है तो वास्तविक लम्बाई `169/130`
यदि छाया 420 cm है वास्तविक लम्बाई है।
`=169/130xx420`
`=546` cm
27.

3 बजे मिनट व घण्टे की सुई द्वारा बनाये गए कोण का मान बताओ?A. `pi//4`B. `pi//3`C. `5pi//12`D. `pi//2`

Answer» Correct Answer - D
hour `=3`
minute `=00`
angle `=|30H-11/2M|`
`=|30xx3-11/2xx0|`
`theta=90`
`theta=90xx(pi)/180=(pi)/2`
28.

if `omega` is a complex fifth roots of unity and `(1+omega+omega^(2)+omega^(3))^(2005)=A+Bomega+Comega^(2)+Domega^(3)` (Where A,B,C,D are real), the `A^(2)+B^(3)+C^(4)+D^(5)=`A. 2B. 1C. 3D. None of these

Answer» Correct Answer - B
`because omega` is a complex fifth roots of unity.
`therefore1+omega+omega^(2)+omega^(3)+omega^(4)=0`
`implies(-omega^(4))^(2005)=A+Bomega+Comega^(2)+Domega^(3)`
`implies-omega^(8020)=A+Bomega+Comega^(2)+Domega^(3)`
`implies-(omega^(5))^(1604)=A+Bomega+Comega^(2)+Domega^(3)`
`implies-1=A+Bomega+Comega^(2)+Domega^(3)`
`impliesA=-1,B=0,C=0,D=0`
29.

If a complex number having absolute value of √2 is making 45° angle with x-axis in third quadrant, then it can be written as –1. [r, θ] = \(\left[ {\sqrt 2 ,\frac{{3\pi }}{4}} \right]\)2. [r, θ] = \(\left[ {\sqrt 2 ,\frac{{\pi }}{4}} \right]\)3. [r, θ] = \(\left[ {\sqrt 2 ,-\frac{{3\pi }}{4}} \right]\)4. [r, θ] = \(\left[ {\sqrt 2 ,-\frac{{\pi }}{4}} \right]\)

Answer» Correct Answer - Option 3 : [r, θ] = \(\left[ {\sqrt 2 ,-\frac{{3\pi }}{4}} \right]\)

CONCEPT:

Point P is uniquely determined by the ordered pair of real numbers (r, θ), called the polar coordinates of the point P.

If P represent the nonzero complex number z = x + iy.

Here \(r = \sqrt {{x^2} + {y^2}} = \left| z \right|\) is called modulus of the given complex number.

The argument of Z is measured from the positive x-axis only.

Let z = r (cos θ + i sin θ) is a polar form of any complex number then following ways are used while writing θ for different quadrants –

For the first quadrant, \({\rm{\theta }} = {\tan ^{ - 1}}\frac{{\rm{y}}}{{\rm{x}}}\)

For the second quadrant \({\rm{\theta }} = {\rm{\pi }} - {\tan ^{ - 1}}\frac{{\rm{y}}}{{\rm{x}}}\)

For the third quadrant \({\rm{\theta }} = - {\rm{\pi }} + {\tan ^{ - 1}}\frac{{\rm{y}}}{{\rm{x}}}\)

For the fourth quadrant \({\rm{\theta }} = - {\rm{\;ta}}{{\rm{n}}^{ - 1}}\frac{{\rm{y}}}{{\rm{x}}}\)

CALCULATION:

Given that \(\left| z \right| = \sqrt 2 \) and angle with x-axis is 45°.

Since its in the third quadrant -

\(\theta = - \pi + \frac{\pi }{4} = - \frac{{3\pi }}{4}\)

⇒ [r, θ] = \(\left[ {\sqrt 2 , - \frac{{3\pi }}{4}} \right]\)

30.

Two series X (x1, x2, x3, x4, ….xn) and Y (y1, y2, y3, y4, ….., yn) are in A.P., such that xn – yn = n − 2. It is also known that x3= b5. Find the value of x99 – y197. (a) 47 (b) 48 (c) 49 (d) 50

Answer»

Correct option  (b) 48

Explanation: 

Let the common difference of the series X be d1 and that of Y be d2

Since xn – yn = n − 2, x1 − y1 = −1 or y1 = x1 + 1 

x3 = y5

x1 + 2d1 = y1 + 4d2

x1 + 2d1= x1 + 1 + 4d2

2d1 − 4d2 = 1 

x99 – y197 = x1+ 98d1 − y1- 196d2 = −1 + 49(2d1− 4d2) = −1 + 49 = 48.

31.

If `A, B, C, D` be the angles of a quadrilateral, prove that : `(tanA+tanB+tanC+tanD)/(cotA+cotB+cotC+cotD) = tan A tan B tan C tan D`A. tan A tan B tan C tan DB. cot A cot B cot C cot DC. `tan^(2)A + tan^(2)B + tan^(2)C + tan^(2)D`D. `sum tan A tan B tanC`

Answer» Correct Answer - A
32.

If AB and AC are two tangents to a circle with centre O such that ∠BOC=110° then ∠CAO = (A) 60° (B) 45° (C) 35° (D) 150°

Answer»

Correct answer is (C) 35°

33.

If `(tan(A+B+C))/(tan(A-B+C))=(tanC)/(tanB)` then `sin2A+sin2B+sin2C` is equal to_______

Answer» `(sin(A+B+C).cos(A-B+C))/(sin(A-B+C)cos(A+B-C))=(sinCcosB)/(sinBcosC)`
`implies(sin2A+sin(2B-2C))/(sin2A-sin(2B-2C))=(sinCcosB)/(sinBcosC)`
Use `C` and `D` rule will get `sin2A+sin2B+sin2C=0`
34.

In ∆ABC, tan\((\frac{A-B}{2})\).tan\(\frac{c}{2}\) =(A) a+b/a-b(B) a2+b2/a2-b2(C) a2-b2/a2+b2(D) a-b/a+b

Answer»

Correct option is: (D) \(\frac{a-b}{a+b}\)

35.

In the given figure QOR is a diameter of a circle and PQ=PR, then ∠PQR = (A) 90° (B) 60° (C) 45° (D) 30°

Answer»

Correct answer is (C) 45°

36.

In the given figure, O is the centre of the circle and ∠QPR = 60° then ∠OQR =(A) 60° (B) 30° (C) 120° (D) 40°

Answer»

Correct answer is (B) 30°

37.

If A is a 3 × 3 non-singular matrix such that AAT = AT A and B = A-1 AT , then BBT = ________. (a) A (b) B (c) I3 (d) BT

Answer»

The correct answer is : (c) l3

38.

Sin α x cot α =(A) 1 (B) cos α(C) cos2α(D) sin2α

Answer»

Correct answer is (B) cos α

39.

If A=[aij]3x3 is any orthogonal matrix then which of the following cannot be true.      |A| = 1|A| = -1|A|=0None of these

Answer»

\(\because\) A is orthogonal matrix.

\(\therefore \) ATA = A.AT = I, where I is identify matrix.

⇒ |ATA| = | I |

⇒ |ATA| |A| = 1    (\(\because\) | I | = 1)

⇒ |A| |A| = 1        (\(\because\) |ATA| = |A|)

⇒ |A|2 = 1

⇒ |A| = -1 or |A| = 1

Hence, |A| = 0 can not be true for an orthogonal matrix A.

40.

Velocity and acceleration vector of a charged particle moving in a magnetic field at some instant are `vecv=3hati+4hatj and veca=2hati+xhatj`. Select the correct options.A. `x=-1.5`B. `x=3`C. Magnetic field is along `z` -directionD. Kinetic energy of the particle is constant

Answer» Correct Answer - A::C::D
acd
41.

Assertion: The lightening conductor at the top of high building has sharp pointed ends. Reason: The surface density of charge at sharp points is very high resulting in setting up of electric wind.A. If both assertion and reason are true and reason correct explanation of assertion.B. If both assertion and reason are true but reason the correct explanation of assertion.C. If assertion is true but reason is false.D. If both assertion and reason are false.

Answer» Correct Answer - A
We know that surface density of charge is very large on the sharp ends of a conductor. This charge from pointed ends sets up a charged electric wind. This charged electric wind comes in contact with the charged cloubs and then source of its building neturalised and so potential drops between building is reduced. Even if lightning strikes the building, charge is conducted by the lightning conductor to the earth and there is no harm to building.
42.

Assertion: The lightening conductor at the top of high building has sharp pointed ends. Reason: The surface density of charge at sharp points is very high resulting in setting up of electric wind.A. Statement I is true, Statement II is True, Statement II is a correct explanation for statement I.B. Statement I is true, Statement II is True, Statement II is Not a correct explanation for statement I.C. Statement I is True, Statement II is False.D. Statement I is False, Statement II is True.

Answer» Correct Answer - A
We know that surface density of a charge is very large on the sharp ends of a conductor. Hence, the lighing conductor conducts chares of lighting to earth and there is no harm to the building.
43.

Two small drops of mercury, each of radius `R`, coalesce to form a single large drop. The ratio of the total surface energies before and after the change isA. `2^(2//3) : 1`B. `sqrt2 : 1`C. `sqrt(1//3) : 1`D. `2 : 1`

Answer» Correct Answer - C
Given that, the two small drops of mercury and radius R of each drop coalesce to form a large drop of radius r, so the net volume remains constant i.e,
initial volume = final volume
`V_("initial")=V_("final")`
`2xx4/3piR^(3)=1dot4/3pir^(3)rArrr=2^(1//3)R` ...(i)
As, surface tension is constant for both the drops.
So, the surface energy of two small drops,
`E_(1)=2xxTA_(1)=2xx4piR^(2)xxT`
Surface energy of one big drop,
`E_(2)=TA_(2)=4pir^(2)xxT=2^(1//3).4piR^(2)T` (using Eq. (i))
Ratio the total surface energy before and after the change is given as,
`E_(1)/E_(2)=(8piR^(2)T)/(2^(2//3)4piR^(2)T)=(2^(1-2/3))/1=2^(1/3):1`
Hence, the ratio of suface energy of the each drop is `2^(1/3) : 1`
44.

The figure shows an isosceles triangle plate of mass `M` and base `L`. The angle at the apex is `90^@`. The apex lies at the origin and the base is parallel to `X-`axis. The moment of inertia of the plate about the `y-`axis isA. `(ML^(2))/(6)`B. `(ML^(2))/(8)`C. `(ML^(2))/(24)`D. None of these

Answer» Correct Answer - A
45.

The figure shows an isosceles triangle plate of mass `M` and base `L`. The angle at the apex is `90^@`. The apex lies at the origin and the base is parallel to `X-`axis. The moment of inertia of the plate about its base parallel to the `x-`axis isA. `(ML^(2))/(18)`B. `(ML^(2))/(36)`C. `(ML^(2))/(24)`D. None of these

Answer» Correct Answer - A
46.

Two infinitely long conducting parallel rails are connected through a capacitor C as shown in Fig. A conductor of length l is moved with constant speed `v_(0)`. Which of the following graph truly depicts the variation of current through the conductor with time? A. B. C. D.

Answer» Correct Answer - C
emf across capacitor is constant and equal to Blv. In steady state, no current flows through the circuit.
47.

A body is dropped from rest from a height h. It covers a distance `(9h)/(25)` in the last seconds of fall. The height h is : (use `g = 9.8 m//sec^(2)` )A. `102.5 m`B. `112.5 m`C. `122.5 m`D. `132.5 m`

Answer» Correct Answer - C
t is the time to reach ground.
`h= (1)/(2) at^(2) , (1 - (9)/(25)) h = (1)/(2) a (t - 1)^(2)`
`(1 - (9)/(25)) = ((t - 1)^(2))/(t^(2)) , (16)/(25) = ((t - 1)^(2))/(t^(2))`
or `(4)/(5) = (t - 1)/(t) :. T = 5 sec`
`h = (1)/(2) xx 9.8 xx 5^(2) = 122.5 m`
48.

Two particles are projected simultaneously from the top of the towers as shown. Find the distance between the towers if they collide in mid air during their flight. A. 15mB. 20mC. `15sqrt(3)m`D. `5sqrt(3)m`

Answer» `vecV+(A//B)` is in directed along AB.
49.

If `vec(A)=hat(i)+2hat(j)+3 hat(k), vec(B)=-hat(i)+hat(j)+4hat(k)` and `vec(C)=3hat(i)-3hat(j)-12 hat(k)`, then find the angle between the vectors `(vec(A)+vec(B)+vec(C))` and `(vec(A)xxvec(B))` in degrees.

Answer» Correct Answer - 90
`vecP=vecA+vecB+vecC=3hati-5hatk` and `vecQ=vecAxxvecB=|(hati,hatj,hatk),(1,2,3),(-1,1,4)|=5hati-7hatj+3hatk`
Angle between `vecP` & `vecQ` is given by `costheta=(vecP.vecQ)/(PQ)=(15-15)/(PQ)=0rArrtheta=90^(@)`
50.

What is the percentage change in the tension necessary in a somometer of fixed length to produce a note one octave lower (half of original frequency) than before?A. `25%`B. `50%`C. `67%`D. `75%`

Answer» Correct Answer - D
In Sonometer
`Vprop sqrt(T)`
`rArr T_(2)=(T_(1))/(4)`
`(T_(1)-T_(2))/(T_(1))xx100=(T_(1)-(T_(1))/(4))/(T_(1))xx100=75%`