Correct Answer: B Most economical section: max hydraulic radius → min wetted perimeter.
Q2.
Which flip-flop has no race condition?
A. SR
B. JK
C. Master-slave JK
D. D
Correct Answer: C Master-slave JK flip-flop eliminates race-around condition.
Q3.
The dry density of soil is maximum at:
A. Liquid limit
B. Plastic limit
C. Optimum moisture content
D. Shrinkage limit
Correct Answer: C Proctor test: maximum dry density at OMC (optimum moisture content).
Q4.
If L and ¬L are both recursively enumerable, then L is:
A. Regular
B. Context-Free
C. Recursive
D. Not recursively enumerable
Correct Answer: C If L and its complement are both RE, then L is recursive (decidable).
Q5.
In an isothermal process, which quantity remains constant?
A. Pressure
B. Volume
C. Temperature
D. Entropy
Correct Answer: C Isothermal: T = constant, PV = constant (for ideal gas).
Q6.
In a min-heap, the smallest element is at:
A. Root
B. Leftmost leaf
C. Rightmost leaf
D. Last node
Correct Answer: A Min-heap property: parent ≤ children, so root is always the minimum element.
Q7.
The first law of thermodynamics is essentially:
A. Conservation of mass
B. Conservation of energy
C. Conservation of momentum
D. Law of entropy
Correct Answer: B ΔU = Q - W (energy conservation for thermodynamic systems).
Q8.
The void ratio of a soil is defined as:
A. Vv/Vs
B. Vv/Vs
C. Vs/Vv
D. Vw/Vv
Correct Answer: B Void ratio e = Vv/Vs (volume of voids / volume of solids).
Q9. General Aptitude
If LOGIC is coded as 15-15-7-9-3, then what is the code for MATH?
A. 1-13-20-8
B. 13-1-20-8
C. 14-1-21-9
D. 12-1-19-7
Correct Answer: C Each letter is coded as its position + 1. L(12)+3=15, O(15)+0=15, G(7)+0=7, I(9)+0=9, C(3)+0=3. For MATH: M(13)+1=14, A(1)+0=1, T(20)+1=21, H(8)+1=9 → 14-1-21-9.
Q10.
Bernoulli's equation is based on:
A. Conservation of mass
B. Conservation of momentum
C. Conservation of energy
D. Continuity
Correct Answer: C P/Ïg + v²/2g + z = constant (energy per unit weight).
Q11. General Aptitude
The sum of ages of A and B is 45 years. 5 years from now, the ratio of their ages will be 4:5. Find the current age of A.
A. 15 years
B. 20 years
C. 25 years
D. 30 years
Correct Answer: A Let A's age = x, B's age = 45-x. After 5 years: (x+5)/(50-x) = 4/5. 5x+25 = 200-4x. 9x = 175. x = 15.
Q12. General Aptitude
The simple interest on ₹1000 at 5% per annum for 2 years is:
A. ₹50
B. ₹100
C. ₹200
D. ₹25
Correct Answer: B SI = P×R×T/100 = 1000×5×2/100 = ₹100.
Q13.
Which language is accepted by Pushdown Automata?
A. Regular
B. Context-Free
C. Context-Sensitive
D. Recursively Enumerable
Correct Answer: B PDA accepts exactly the class of Context-Free Languages (CFL).
Q14.
In orthogonal cutting, the cutting edge is:
A. Parallel to work surface
B. Perpendicular to cutting velocity
C. At 45°
D. Inclined
Correct Answer: B Orthogonal cutting: cutting edge ⊥ to cutting velocity direction.
Q15.
In an RC circuit, the time constant is:
A. R + C
B. RC
C. R/C
D. C/R
Correct Answer: B Ï„ = RC (time for voltage to reach 63.2% of final value).
Q16. General Aptitude
Which word is opposite in meaning to "Benevolent"?
A. Kind
B. Generous
C. Malevolent
D. Charitable
Correct Answer: C Benevolent = kind/generous. Opposite = malevolent (wicked/hostile).
Q17.
The bandwidth of an ideal bandpass filter is:
A. Zero
B. Equal to center frequency
C. Difference of cut-off frequencies
D. Infinite
Correct Answer: C BW = fH - fL where fH and fL are upper and lower cut-off frequencies.
Q18.
The material used for cutting tools is:
A. Mild steel
B. HSS (High Speed Steel)
C. Cast iron
D. Brass
Correct Answer: B HSS retains hardness at high cutting temperatures (used for drills, end mills).