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Correct Answer Logic:
The bar for activity 3 reaches 48 on the vertical axis.
Uploaded by: Fani Warraich
Correct Answer Logic:
Simplifying the product: \(\cos(\frac{\pi}{6}+x)\cos(\frac{\pi}{6}-x) = \frac{1}{2}[\cos(\frac{\pi}{3}) + \cos(2x)] = \frac{1}{2}[\frac{1}{2} + \cos 2x] = \frac{1}{4} + \frac{\cos 2x}{2}\). The equation becomes: \(8\cos x(\frac{1}{4} + \frac{\cos 2x}{2} - \frac{1}{2}) = 1\), which gives \(8\cos x(\frac{\cos 2x}{2} - \frac{1}{4}) = 1\), or \(4\cos x(\cos 2x - \frac{1}{2}) = 1\). Since \(\cos 2x = 2\cos^2 x - 1\): \(4\cos x(2\cos^2 x - 1 - \frac{1}{2}) = 1\), giving \(4\cos x(2\cos^2 x - \frac{3}{2}) = 1\), or \(8\cos^3 x - 6\cos x - 1 = 0\). Solving this cubic and finding solutions in [0,ฯ€], then summing them gives \(k = \frac{2}{3}\).
Uploaded by: Fani Warraich
Dairy Food Science and Technology QUESTION #5915
Question 3
The detection of alkali (neutralizer) addition to milk uses which test?
  • Alizarin test or Rosalic acid testโœ”๏ธ
  • Clot on boiling test
  • Alcohol precipitation test
  • Gerber test
Correct Answer Logic:
Alizarin changes color depending on milk \(\text{pH}\): yellow in acidic milk and pink/red in alkaline milk. The Rosalic acid test similarly detects added alkalis (\(\text{NaHCO}_3\), \(\text{Na}_2\text{CO}_3\), \(\text{NaOH}\)) used by adulterators to neutralize sour milk. Normal milk gives a yellow-brown color.
Uploaded by: Fani Warraich
General Abilities QUESTION #7974
Question 4
5448 rounded off to the nearest 1000 is:
  • 6000
  • 5400
  • 5000โœ”๏ธ
  • 4500
Correct Answer Logic:
Since the hundreds digit is 4 (i.e., 448 < 500), we round down: \(5448 \approx 5000\).
Uploaded by: Fani Warraich
Chemistry QUESTION #7497
Question 5

In which of the following processes is the change in oxidation state equal to five?

  • $\text{C}_2\text{O}_4^{2-} \to 2\text{CO}_2$
  • $\text{MnO}_4^- \to \text{Mn}^{2+}$โœ”๏ธ
  • $\text{Cr}_2\text{O}_7^{2-} \to 2\text{Cr}^{3+}$
  • $\text{CrO}_4^{2-} \to \text{Cr}^{3+}$
Correct Answer Logic:

Calculate the change in oxidation state for each:

  • (A) C in C$_2$O$_4^{2-}$: $+3$; C in CO$_2$: $+4$. Change $= +1$ per C atom (2 C, so total = 2, but per atom = 1).
  • (B) Mn in MnO$_4^-$: $+7$; Mn in Mn$^{2+}$: $+2$. Change $= 7 - 2 = \mathbf{5}$ โœ“
  • (C) Cr in Cr$_2$O$_7^{2-}$: $+6$; Cr in Cr$^{3+}$: $+3$. Change $= 3$ per Cr atom.
  • (D) Cr in CrO$_4^{2-}$: $+6$; Cr in Cr$^{3+}$: $+3$. Change $= 3$.

The change of 5 occurs in the conversion $\text{MnO}_4^- \to \text{Mn}^{2+}$.

Uploaded by: Fani Warraich
Physics QUESTION #416
Question 6
If inductance is denoted by L and resistance by R
  • which of the following is true for a choke?โœ”๏ธ
  • R is large, L is very small
  • R is very small, L is large
  • Both R and L are large
Correct Answer Logic:
1
Uploaded by: Fani Warraich
MCQs Section QUESTION #4890
Question 7
Which word is opposite to "CONSCIENTIOUS"
  • Uncorrupt
  • Honourable
  • Principled
  • Profligateโœ”๏ธ
Correct Answer Logic:
Conscientious means wishing to do one's work thoroughly and carefully. Its antonym is Profligate, meaning recklessly wasteful and utterly lacking in moral principles.
Uploaded by: Fani Warraich
General Knowledge QUESTION #2637
Question 8
The EXTERNAL DATA BUS (EDB) in a computer is best described as:
  • A type of USB cable used to connect external drives to the computer
  • A row of wires that interconnect the parts of the computer internallyโœ”๏ธ
  • A software interface that manages communication between the operating system and hardware
  • The physical slot on the motherboard where expansion cards are inserted
Correct Answer Logic:
The External Data Bus (EDB) is a row of wires that interconnect the parts of our computer. It acts as the pathway through which data travels between the CPU, RAM, and other components. Think of it as the roads or highways through which data travels inside the computer.
Uploaded by: Fani Warraich
Correct Answer Logic:
Since the glow occurs 'only when disturbed,' it is not constant, thus it is 'intermittent.'
Uploaded by: Fani Warraich
General Knowledge QUESTION #4752
Question 10
Former US Vice-President Al Gore was awarded the Nobel Peace Prize in 2007 for his campaign against which issue?
  • Child Labour
  • Human Rights Violations
  • Global Warming and Climate Changeโœ”๏ธ
  • Nuclear Proliferation
Correct Answer Logic:
Al Gore, along with the Intergovernmental Panel on Climate Change (IPCC), won the 2007 Nobel Peace Prize for their work to raise global awareness of climate change and global warming.
Uploaded by: Fani Warraich
General Knowledge QUESTION #2599
Question 11
A PDA (Personal Digital Assistant) made a significant contribution to computing history primarily by:
  • Introducing the first graphical user interface
  • Allowing computing to go mobile for the first timeโœ”๏ธ
  • Developing the first internet browser
  • Creating the first spreadsheet application
Correct Answer Logic:
A PDA (Personal Digital Assistant) allows computing to go mobile. It was a handheld device combining computing, communication, and organizational tools โ€” a key step toward today's smartphones and tablets.
Uploaded by: Fani Warraich
Chemistry QUESTION #7386
Question 12
Which series of spectral lines of the hydrogen atom falls in the visible region?
  • Lyman series
  • Balmer seriesโœ”๏ธ
  • Paschen series
  • Brackett series
Correct Answer Logic:
Hydrogen spectral series and their regions:
  • Lyman (\(n\to1\)): UV region
  • Balmer (\(n\to2\)): Visible region (400โ€“700 nm)
  • Paschen (\(n\to3\)): Near IR
  • Brackett (\(n\to4\)): IR
  • Pfund (\(n\to5\)): Far IR
The Balmer series (H\(\alpha\) at 656 nm red, H\(\beta\) at 486 nm blue, etc.) was the first discovered because it falls in the visible range.
Uploaded by: Fani Warraich
Electrical Engineering QUESTION #2191
Question 13
Using Gauss's law, an infinite line charge with $\rho_L = 20\,\text{nC/m}$ in free space produces an electric field at $r = 5\,\text{cm}$ of:
  • $7{,}193\,\text{V/m}$โœ”๏ธ
  • $3{,}597\,\text{V/m}$
  • $14{,}386\,\text{V/m}$
  • $1{,}798\,\text{V/m}$
Correct Answer Logic:
$E = \frac{\rho_L}{2\pi\epsilon_0 r} = \frac{20\times10^{-9}}{2\pi\times8.854\times10^{-12}\times0.05} = \frac{20\times10^{-9}}{2.781\times10^{-12}} \approx 7{,}193\,\text{V/m}$.
Uploaded by: Fani Warraich
Biology QUESTION #7279
Question 14
Which one of the following is commonly used to transfer foreign DNA into crop plants?
  • Penicillium expansum
  • Trichoderma harzianum
  • Meloidogyme incognita
  • Agrobacterium tumefaciensโœ”๏ธ
Correct Answer Logic:
Agrobacterium tumefaciens is a soil bacterium used extensively as a natural genetic engineer in plant transformation. Its Ti (tumour-inducing) plasmid can be modified to carry a gene of interest and insert it stably into the plant genome. It is the most widely used vector for introducing foreign genes into dicot crop plants.
Uploaded by: Fani Warraich
Chemistry QUESTION #472
Question 15
Na may be denoted by __________ electron configuration notation
  • 1s?2s?
  • [Ar] 4s?
  • [Ne] 3s?โœ”๏ธ
  • None of these
Correct Answer Logic:
Sodium: [Ne] 3s?
Uploaded by: Fani Warraich
Civil Procedure QUESTION #3757
Question 16
What is the 'Rule Against Perpetuities' (RAP) designed to prevent?
  • Landlords charging too much rent.
  • Property interests from vesting too far into the future (dead hand control).โœ”๏ธ
  • Neighbors from building fences too high.
  • The government from taking land without compensation.
Correct Answer Logic:
RAP invalidates any interest in property that might not vest within 21 years of a 'life in being' at the time of the creation of the interest.
Uploaded by: Fani Warraich
Home Economics QUESTION #6253
Question 17
According to Jean Piaget, the stage where children begin to think logically about concrete events is:
  • Sensorimotor
  • Preoperational
  • Concrete Operationalโœ”๏ธ
  • Formal Operational
Correct Answer Logic:
The Concrete Operational stage typically occurs between ages 7 and 11.
Uploaded by: Fani Warraich
Boilers Mechanical Engineering QUESTION #2448
Question 18
The centrifugal force \(F_0\) generated by an unbalanced rotating mass \(m_0\) at eccentricity \(r\) rotating at speed \(p\) (rad/s) is:
  • \(F_0 = m_0 r p\)
  • \(F_0 = m_0 r p^2\)โœ”๏ธ
  • \(F_0 = m_0 r^2 p\)
  • \(F_0 = m_0 g r\)
Correct Answer Logic:
The centrifugal force from an unbalanced rotating mass: \(F_0=m_0 r p^2\), where \(m_0\) is the unbalance mass, \(r\) is the eccentricity, and \(p\) is the angular speed.
Uploaded by: Fani Warraich
Boilers Mechanical Engineering QUESTION #2525
Question 19
Conservation of linear momentum applies to a system of particles when:
  • Kinetic energy is conserved
  • The net external force on the system is zero: \(\sum\mathbf{F}_{ext}=0\)โœ”๏ธ
  • All particles move with the same velocity
  • The system has no angular momentum
Correct Answer Logic:
Linear momentum of a system \(\mathbf{G}=\sum m_i\mathbf{v}_i\) satisfies \(\frac{d\mathbf{G}}{dt}=\sum\mathbf{F}_{ext}\). When \(\sum\mathbf{F}_{ext}=0\), \(\mathbf{G}\) is conserved.
Uploaded by: Fani Warraich
Correct Answer Logic:
Relative speed (moving towards each other) \(= 80 + 70 = 150\) km/h. Time \(= \dfrac{300}{150} = 2\) hours.
Uploaded by: Fani Warraich