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 relation between geometrical length (Lg) of a magnet and its magnetic length (Lm) is -(A) Lm = 5/6 Lg(B) Lm = 6/5 Lg(C) Lm = Lg(D) Lm = 2Lg

Answer»

Correct answer is (A) Lm = 5/6 Lg

2.

The focal lengths of the objective and eye lenses of a telescope are respectively 200 cm and 5 cm . The maximum magnifying power of the telescope will beA. `-100`B. `-60`C. `-48`D. `-40`

Answer» Correct Answer - C
Magnifying power , `M=f_0/(f_e) (1+ (f_e)/d)`
Least distance of distinct vision , d= 25 cm
`M=-200/5 (1+5/25) =-40 (1+1/5)`
`=-40 (6/5)` =-48 cm .
3.

Which of the following is correct for total electric flux from the whole surface, if +q charge is placed inside any spherical surface?(A) q x ∈0(B) \(\frac{q}{\in_0}\)(C) \(\frac{\in_0}{q}\)(D) \(\frac{q^2}{\in_0}\)

Answer»

Correct answer is (B) \(\frac{q}{\in_0}\)

4.

If + q charge is placed inside any spherical surface then total flux coming out from whole surface will be-(A) q x ε0(B) q x ε0(C)  ε0/q(D) q2/ε0

Answer»

Correct answer is (B) q x ε0

5.

Equivalent focal lenght of two lenses in contact having power = 15D and + 5D will be-(A) -20 cm(B) -10 cm(C) +10 cm(D) +20 cm

Answer»

Correct answer is (B) -10 cm

6.

In an alternating current circuit, the phase difference between current i and voltage in ϕ then the wattless component of current will be-(A) I cos ϕ (B) I tan ϕ (C) I sin ϕ (D) I cos2 ϕ 

Answer»

Correct answer is (C) I sin ϕ 

7.

The mechanical advantage of a machine is 2. It is used to raise a load of 15kgf. What effort is needed.

Answer»

Given,

Mechanical advantage = 2

Load = 15 Kgf

Mechanical advantage = load/Effort

Effort = Load/Mechanical advantage

= 15/2 = 7.5 kgf

8.

जेनर डायोड का उपयोग किसमें होता है

Answer»

जेनर डायोड का व्यापक रूप से प्रयोग एक सर्किट में वोल्टेज को नियंत्रित रखने के लिए किया जाता है। रिवर्स-बायस्ड करने के लिए जब इसे एक परिवर्ती वोल्टेज के स्रोत के साथ समानांतर रूप से जोड़ा जाता है, तो वोल्टेज, डायोड के रिवर्स ब्रेकडाउन वोल्टेज तक पहुंचने से जेनर डायोड संचालित होता है। उस बिंदु से वह वोल्टेज को उसी मूल्य पर रखता है।

9.

the wheels of a car increase their rate of rotation from 1.0 rev/s to 8.0 rev/s in 20s calculate the angular acceleration of the wheel?

Answer»

Let æi  represents initial angular speed and ærepresents final angular speed. let % represent pie.

let f&ff are frequencies initially and finally.

f= 2 rev/sec         f = 8 rev/sec

æi = 2%f= 2% rad/sec        æ= 2%f= 16%  rad/sec          del æ=d æ =æ- æ= 14% rad/sec

let ais angular acceleration

a= d æ / dt = 14% /  20 = 0.7 rad/sec2

Proof:   æf = æ+ ac * t = 2% + 0.7*20 = 16% rad/sec

10.

If concave mirror forms a real, inverted image in front of the mirror, then how can we see our inverted image behind the concave surface of a spoon?

Answer»

Concave surface of the spoon forms the virtual image of the real image from by the spoon (which here acts as the concave mirror). Since spoon is a metallic surface, reflection forms the inverted image.

11.

The voltage out of a bridge rectifier is a a. Half-wave signal b. Full-wave signal c. Bridge-rectified signal d. Sine wave

Answer»

9b) Full-wave signal

12.

A transformer has a turns ratio of 4: 1. What is the peak secondary voltage if 115 V rms is applied to the primary winding? a. 40.7 V b. 64.6 V c. 163 V d. 650 V

Answer»

The correct answer is: (a)  40.7 V

13.

Line voltage may be from 105 V rms to 125 rms in a half-wave rectifier. With a 5:1 step-down transformer, the maximum peak load voltage is closest to a. 21 V b. 25 V c. 29.6 V d. 35.4 V

Answer»

The correct answer is: (d) 35.4 V

14.

Diamond is very hard because …………….. (a) it is covalent solid (b) it has large cohesive energy(c) high melting point (d) insoluble in all solvents

Answer»

(b) it has large cohesive energy

15.

Kinetic energy of emitted electron depends upon (a) frequency (b) intensity (c) nature of atmosphere surrounding the electron (d) none of these

Answer»

(a) frequency

Kinetic energy of emitted electron depends on the frequency of incident radiation.

16.

With a half-wave rectified voltage across the load resistor, load current flows for what part of a cycle? a. 0 degrees b. 90 degrees c. 180 degreesd. 360 degrees

Answer»

(c) 180 degrees

17.

The ratio between the first three orbits of hydrogen atom is………(a) 1:2:3 (b) 2:4:6(c) 1:4:9 (d) 1:3:5

Answer»

 (c) 1:4:9

En = \(\frac{-13.6 \times z^2}{n^2}\)

n = 1; E =- 13.6 eV/ atom 

n = 2; E = – 3.4 eV/ atom 

n = 3; E = -1.51 eV/atom     

The ratio of three orbits E1 : E2 : E3 = 13.6 : 3.4 : 1.51 = 1 : 4 : 9

18.

If a half-wave rectified voltage is fed to a load resistor, which part of a cycle the load current will flow?(a) 0° – 90° (b) 90° – 180° (c) 0° – 180° (d) 0° – 360°

Answer»

(c) 0° – 180°

19.

Bohr’s theory of hydrogen atom did not explain fully (a) diameter of H-atom (b) emission spectra (c) ionisation energy(d) the fine structure of even hydrogen spectrum

Answer»

(d) the fine structure of even hydrogen spectrum

 Bohr theory could not explain the five structure of hydrogen spectrum.

20.

An electric iron of resistance 20Ω takes a current of 5A. Calculate the heat developed in 30 s

Answer»

The amount of heat(H)produced is given by the joule’s law of heating as, H = VIt, where 

Current, I = 5A 

Time, t = 30s 

∴ Voltage, V = I * R = 5 * 20 = 100 V 

∴ H = 100 * 5 * 30 = 1.5 * 104 J 

Therefore, the amount of heat developed in the electric iron is 1.5 * 104 J.

21.

How is telescope classified ?

Answer»

According to optical property, it is classified into two groups:

1. refracting telescope

2. reflecting telescope

22.

A ball is thrown vertically upwards with an initial velocity of `5 m//sec` from point `P` as shown `Q` is a point `10 m` vertically below the point `P`. Then the speed of ball at point `Q` will be : (take `g=10 m//s^(2)` and neglect air resistance) A. `7.5 m//sec`B. `10 m//sec`C. `15 m//sec`D. `17.5 m//sec`

Answer» Correct Answer - C
`v2 =u2 +2 as`
`v2 =(5)_(2) +2 xx 10 xx 10`
`v2 =25 +200 rArr 225`
`v =15 m//sec`.
23.

2x-y=5 or 4x+2y=10 ka smikarn

Answer»

\(2x - y = 5\)

⇒ \(4x - 2y = 10\)    ....(1)

\(4x + 2y = 10\)        .....(2)

By adding both equations, we get 

\(8x = 20\)

⇒ \(x = \frac{20}8 = \frac52\)

\(\therefore y = 2x - 5 = 5 - 5 = 0\)

Hence, x = \(\frac52\), y = 0 is solution of given system of equations.

24.

1. If \( A=\left\{0, \frac{\pi}{6}, \frac{\pi}{4}, \frac{\pi}{3}, \frac{\pi}{2}\right\} \) and \( f: A \rightarrow B \) is a surjection defined by \( f(x)=\cos x \), then find \( B \).

Answer»

\(f: A \to B\) is a surjection and defined by \(f(x) = cos x\)

Then \(f(A) = B\)

But \(A = \left\{0, \frac\pi6, \frac\pi4,\frac\pi3,\frac\pi2\right\}\)

\(\therefore f(A) = \left\{cos 0, cos\frac\pi6, cos\frac\pi4, cos\frac\pi3, cos\frac\pi2\right\}\)

\(= \left\{1, \frac{\sqrt3}{2}, \frac1{\sqrt2}, \frac12, 1\right\}\)

\(\therefore B = \left\{1,\frac{\sqrt3}2, \frac1{\sqrt2},\frac12, 1\right\}\)

25.

The term independent of ' \( x \) ' in the expansion of \( \left(2+\sqrt{x}-\frac{4}{\sqrt{x}-2}\right)^{-40} \) is

Answer»

 (2 + √x + 4/(√x - 2))-40

 = \((\frac{x-4+4}{\sqrt x-2})^{-40}\)

 = x-40(√x - 2)40

 = x -40(\(\sum\limits_{r=0}^{40}\) 40Cr x \(\frac{40-r}2\)(-2)r), 0\(\leq\)\(\leq\) 40

 = \(\sum\limits_{r=0}^{40}\) 40Cr x\(-(\frac{40-r}2)\)(-2)2

For independent term-(\(\frac{40+r}2=0\))

⇒ r = -40 which is not positive.

Hence, independent term in expansion of (2 + √x + \(\frac4{\sqrt4 - 2}\))-40 is 0.

\(\left(2+\sqrt x - \frac 4 {\sqrt x -2}\right)^{-40} = \left(\frac{x- 4 - 4}{\sqrt x - 2}\right)^{-40}\)

\(= (x - 8) ^{-40} ( \sqrt x - 2)^{40}\)

\(= x^{-40} \left(1 - \frac8 x\right)^{-40} (\sqrt x - 2^{40})\)

\(= x^{-40} \left( \displaystyle\sum^{40}_{r=0} \,^{40}C_r \;x^{\frac{40 - r}2} \;(-2)^r\right) \left(1 - \frac8x\right)^{-40}\)

\(= \left(\displaystyle\sum^{40}_{r = 0} (-1)^r 2^r \,^{40}C_r\; x^{\left(\frac{40 + r}2\right)}\right)\left(1 - \frac8x\right)^{-40}\)

\(= \left(\displaystyle\sum^{40}_{r = 0} (-1)^r 2^r \,^{40}C_r\; x^{\left(\frac{40 + r}2\right)}\right)\left(\displaystyle\sum^\infty_{k = 0}\frac{n(n + 1)...(n + k - 1)}{k!} x^k\right), n = 40;k\in Z\)

\(= \displaystyle\sum^{40}_{r = 0} \displaystyle\sum^\infty_{k =0} ( -1)^r 2^r \,^{40}C_r \frac{n (n + 1)....(n + k - 1)}{k!} x^{-\frac{40+r}2+ k} , n = 40;k\in Z\)

For independent term 

\(-\frac{40 + r}{2} + k = 0\)

⇒ \(k = \frac{40 + r}{2}\)

and \(0 \le r\le 40\)

∴ Independent term = \(\displaystyle\sum^{40}_{r = 0\\r = even} 2^r \, ^{40} C_r \frac{40. 41.42. ......\left(\frac{r + 118}2\right)}{\left(\frac{40 + r}{2}\right)!}\)

26.

If \( \overrightarrow{ A }=2 \hat{ i }+\sqrt{7} \hat{ j } \) and \( \overrightarrow{ B }=5 \hat{ i }+\sqrt{7} \hat{ j }-3 \hat{ k } \), then the vector whose magnitude is equal to \( \overrightarrow{ A } \cdot \overrightarrow{ B } \) and parallel to \( \overrightarrow{ B }-\overrightarrow{ A } \) is :(A) \( \frac{17}{\sqrt{2}}(\hat{k}-\hat{j}) \)(B) \( \frac{17}{\sqrt{2}}(\hat{i}-\hat{k}) \)(C) \( 3 \hat{i}-3 \hat{k} \)(D) \( 3 \hat{k}-3 \hat{i} \)

Answer»

\(\vec{B} - \vec{A} = 3\hat{i} - 3\hat{k}\) (direction)

\(\vec{A}.\vec{B} = (2.5 + \sqrt{7}\sqrt{7}) = 17\) (magnitude)

\(\frac{17}{\sqrt{2}} (\hat{i} - \hat{k})\)  Ans Option B

27.

The sum and difference of two vectors are perpendicular to each other. Prove that the vectors are equal in magnitude.

Answer»

As the vector \(\vec A+\vec B \) and \(\vec A-\vec B\) are perpendicular to each other, therefore

\((\vec A+\vec B).(\vec A-\vec B)=0\)

\(\vec A.\vec A-\vec A.\vec B+\vec B.\vec A-\vec B.\vec B=0\)

or  A2 - B2 = 0

A = B  (∵ \(\vec A.\vec B=\vec B.\vec A\))

28.

Define superposition principle.

Answer»

The principle of superposition states that, the total response (in the form of motion or force etc) will be a result of the algebric addition of all stimuli at a given point in space-time.

29.

Which are both converging optical instrument?

Answer»

 A microscope has two converging lenses. This is because it is easier to get higher magnification with two lenses rather than just one.

30.

Polarization is the property of?

Answer»

Polarization, property of certain electromagnetic radiations in which the direction and magnitude of the vibrating electric field are related in a specified way. A polarizing filter has its molecules all aligned in the same direction.

31.

Polarization of reflection: Brewster law explain

Answer»

Brewster's law, relationship for light waves stating that the maximum polarization (vibration in one plane only) of a ray of light may be achieved by letting the ray fall on a surface of a transparent medium in such a way that the refracted ray makes an angle of 90° with the reflected ray.

32.

Polarization is a property of

Answer»

Polarization, property of certain electromagnetic radiations

33.

Cl2O is mixed anhydride of 

Answer»

Mixed anhydride of HClO2​ and HClO3

ClO2​ reacts with KOH forming KClO3​ and KClO2

2KOH+2ClO2​→KClO2​+KClO3​+H2​O

This reaction indicates that ClO2​ is a mixed anhydride of HClO2​ and HClO3​.

34.

Fill in the blanks in the following sentences with suitable forms (after adding a prefix/suffix) of the words in brackets. 1. He was acting in a very ........ way. (child). 2. This word is very difficult to spell, and even worse, its ......... (pronounce) 3. You shouldn’t have done that! it was very ....... of you. (think) 4. He didn’t pass his exam. He was .......... in the second attempt (succeed) 5. Some of the Indian cities are dreadfully .......... (crowd) 6. The team won the ............. (champion) 7. There is a very high ........... that they will be late. (likely) 8. I couldn’t find any ......... in his theory. (weak) 9. There was a three-hour ............because of the strike. (stop) 10. You need a motivation, organizatiòn and revision to learn ......... English. (combine)

Answer»

1) childish 

2) pronunication 

3) ill thinking 

4) successful 

5) crowdy

6) championship 

7) likelihood 

8) weakness 

9) stoppage 

10) combination

35.

What is the self linking property of an atom known as?

Answer»

The self linking property of an atom known as Catenation.

36.

In which of the following compounds, the `C-Cl` bond ion-isation shall give most stable carbonium ion?A. B. C. D.

Answer» Correct Answer - D
37.

Apart from Mahabharata, there is a Ghatotkacha that comes in Indian history as son of Srigupta-former chief of Pataliputra. Can you name the dynasty that ruled over Ganga Valley around 3rd century AD

Answer»

Correct Answer is Lichchavis

38.

Dr Patrick Russel (1727-1805) came to India and pioneered the study of what?

Answer»

Father of Indian Ophiology

39.

The average life span of RBC is 120 days. 1. Write the places where RBC is produced and destroyed? 2. Name respiratory pigment in Human RBC.

Answer»

1. RBS are produced in red bone marrow and destroyed in spleen 

2. Haemoglobin

40.

Which Cells is a fourth, less visible, epidermal cell. 1. Merkel cell 2. Skin cells 3. Immune cells

Answer»

Correct option: 1 Merkel cell

41.

Stratum corneum layer is also known as a 1. Horny layer 2. Granular layer 3. Basal layer

Answer»

Correct option: 1. horny layer

42.

Consider the compounds, BCl3 and CCl4 . How will they behave with water?

Answer»

The B atom in BCl3 has only six electrons in the valence shell and hence is an electrondecient molecule. It easily accepts a pair of electrons donated by water and hence BCl3 undergoes hydrolysis to form boric acid (H3BO3) and HCl.

BCl3 + 3H2O → H3BO3 + 3HCl

In contrast, C atom in CCl4 has 8 electrons in the valence shell. Therefore, it is an electron-precise molecule. As a result, it neither accepts nor donates a pair of electrons. In simple words, it does not accept a pair of electrons from H2O molecule and hence CCl4 does not undergo hydrolysis in water.

43.

‘Generally, non-metal oxides are basic.’ 1. Do you agree? 2. What do you meant by oxides? 3. Which are the different types of oxides? 4. Give examples for each type of oxides.

Answer»

1. No. Generally, non metallic oxides are acids.

2. The binary compounds formed by the combination of oxygen with metals or nonmetals are called oxides. 

3. Acidic oxides, basic oxide, amphoteric oxide, neutral oxide. 

4. Acidic oxide → SO2 , NO2 

Basic oxide → MgO 

Amphoteric oxide → Al2O3 , ZnO 

Neutral oxide → CO, N2O

44.

1. Name the allotropes of carbon. 2. Carbon monoxide is highly poisonous. Do you agree? Justify.

Answer»

1. Graphite, diamond and fullerene. 

2. I agree with this statement. Because, CO has strong and reversible binding with haemoglobin resulting in the formation of carboxy haemoglobin. This reduces the amount of haemoglobin available in blood for oxygen transport. This causes laboured respiration, muscle weakness and even death.

45.

Find the correct matchA. Mustard plant : Opposite phyllotaxyB. Mustard plant : Alternate phyllotaxyC. Guava plant : Alternate phyllotaxyD. Guava plant : Whorled phyllotaxy

Answer» Correct Answer - B
46.

In cyathium inflorescenceA. single male flower is surrounded by female flowersB. male and female flowers are borne in different plantsC. there is only one male and one female flowerD. single female flower is surrounded by many peripheral male flowers

Answer» Correct Answer - D
47.

(a) Write the palindromic nucleotide sequence for the following DNA segment:5′ - GAATTC - 3′(b) Name the restriction endonuclease that recognizes this sequence. (c) How are ‘sticky ends’ produced? Mention their role

Answer»

(a) 5' – GAATTC – 3' 

3' – CTTAAG – 5' 

(b) EcoRI is the restriction endonuclease that recognizes this palindrome. 

(c) When the restriction enzyme cuts the DNA strands a little away from the center of the palindromic sequence, between the same two bases on both the strands, sticky ends are produced.

  • The stickiness of the ends facilitates the action of the enzyme DNA-ligase.
48.

Beads on string like structures of A are seen in B, which further condense to form chromosomes in C stage of cell division. Identify A, B, C.A. `{:(" A B C"),("Chromonema Chromatin Metaphase"):}`B. `{:(" A B C"),("Chromatin Chromatid Metaphase"):}`C. `{:(" A B C"),("Chromonema Chromosome Anaphase"):}`D. `{:(" A B C"),("Chromonema Chromatid Anaphase"):}`

Answer» Correct Answer - A
49.

Select the correct statement with respect to mitosisA. Chromatids separate but remain in the centre of the cell in anaphaseB. Chromatids start moving towards opposite poles in telophaseC. Golgi complex and endoplasmic reticulum are still visible at the end of prophaseD. Chromosomes move to the spindle equator and get aligned along equatorial plate in metaphase

Answer» Correct Answer - D
50.

Select the correct combination of the statements (i-iv) regarding the characteristics of certain organisms. (i) Methanogens are archaebacteria which produce methane in marshy areas (ii) Nostoc is a filamentous blue-green alga which fixes atmospheric nitrogen (iii) Chemosnthetic autotrophic bacteria synthesise cellulose from glucose (iv) Mycoplasma lack a cell wall and can survive without oxygen The correct statements areA. (ii) and (iii)B. (i),(ii) and (iii)C. (ii),(iii) and (iv)D. (i),(ii) and (iv)

Answer» Correct Answer - D