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GIKI Test practice questions

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Question 1Electrical Engineering

A 100 Ω resistor carries a current of 0.5 A. What is the power dissipated in the resistor?

  1. 200 W
  2. 100 W
  3. 25 W Correct answer.
  4. 50 W

Explanation

Power in a resistor can be computed as P = I²R = (0.5)² × 100 = 0.25 × 100 = 25 W. Equivalently, the voltage is V = IR = 50 V and P = VI = 50 × 0.5 = 25 W. Both routes confirm the same result.

Question 2Electrical Engineering

Two resistors of 6 Ω and 3 Ω are connected in parallel. What is the equivalent resistance of the combination?

  1. 9 Ω
  2. 2 Ω Correct answer.
  3. 1.5 Ω
  4. 4.5 Ω

Explanation

For two resistors in parallel, R_eq = (R1 × R2)/(R1 + R2) = (6 × 3)/(6 + 3) = 18/9 = 2 Ω. The equivalent resistance of a parallel pair is always smaller than the smallest branch resistance, which 2 Ω satisfies.

Question 3Electrical Engineering

In a purely capacitive AC circuit, the current waveform has which phase relationship to the applied voltage?

  1. Current lags voltage by 90°
  2. Current is in phase with voltage
  3. Current leads voltage by 90° Correct answer.
  4. Current leads voltage by 45°

Explanation

The impedance of a capacitor is 1/(jωC), which carries a −90° angle, so the current through it leads the voltage across it by 90°. This is often remembered with the mnemonic CIVIL: in a capacitor (C), current (I) leads voltage (V).

Question 4Electrical Engineering

A silicon pn-junction diode is forward biased. Which condition best describes when it conducts appreciable current?

  1. When the applied forward voltage exceeds roughly 0.7 V Correct answer.
  2. When the applied forward voltage exceeds roughly 0.2 V
  3. When the applied reverse voltage exceeds the breakdown voltage
  4. When the junction temperature is held at absolute zero

Explanation

A silicon diode needs about 0.6 to 0.7 V of forward bias to overcome the built-in potential barrier before significant current flows. Below this knee voltage the current is very small. Germanium diodes, by contrast, turn on nearer 0.2 to 0.3 V.

Question 5Electrical Engineering

What is the primary function of a transformer in an electrical power system?

  1. To change AC voltage levels while transferring power magnetically Correct answer.
  2. To increase the frequency of the supply
  3. To convert AC into DC by rectification
  4. To store energy in an electric field for later release

Explanation

A transformer uses mutual induction between windings to step AC voltage up or down while ideally preserving the power level. The turns ratio sets the voltage ratio, and the current ratio varies inversely. Transformers do not change frequency and work only with alternating quantities.

Question 6Electrical Engineering

Which binary number is equivalent to the decimal value 13?

  1. 1110
  2. 1011
  3. 1001
  4. 1101 Correct answer.

Explanation

Reading 1101 as powers of two gives 1×8 + 1×4 + 0×2 + 1×1 = 13. The place values from left to right are 8, 4, 2, and 1.

Question 7Electrical Engineering

A coil of 200 turns links a magnetic flux that changes at a rate of 0.05 Wb/s. What EMF is induced in the coil?

  1. 40 V
  2. 10 V Correct answer.
  3. 2.5 V
  4. 0.25 V

Explanation

Faraday's law with N turns gives e = N × dΦ/dt = 200 × 0.05 = 10 V. The induced EMF is proportional to both the number of turns and the rate of flux change.

Question 8Electrical Engineering

An ideal op-amp is configured as a non-inverting amplifier with a feedback resistor of 90 kΩ and a ground resistor of 10 kΩ. What is the closed-loop voltage gain?

  1. −9
  2. 10 Correct answer.
  3. 0.1
  4. 9

Explanation

For the non-inverting configuration, gain = 1 + (Rf/R1) = 1 + (90/10) = 10. The input signal is applied to the non-inverting terminal, so the gain is positive and at least one.

Question 9Electrical Engineering

A first-order RC low-pass filter has R = 1 kΩ and C = 1 µF. What is its approximate cutoff frequency?

  1. 159 Hz Correct answer.
  2. 159 kHz
  3. 1.59 kHz
  4. 1 kHz

Explanation

The −3 dB cutoff is f_c = 1/(2πRC). Here RC = 1000 × 1×10⁻⁶ = 1×10⁻³ s, so f_c = 1/(2π × 10⁻³) ≈ 159 Hz.

Question 10Electrical Engineering

In a three-phase star-connected supply, the line voltage is 400 V. What is the approximate phase voltage?

  1. 692 V
  2. 230 V Correct answer.
  3. 200 V
  4. 400 V

Explanation

For a star connection, V_line = √3 × V_phase, so V_phase = 400/√3 ≈ 231 V, commonly quoted as 230 V. In a star system the phase voltage is always lower than the line voltage by the factor √3.

Question 11Electrical Engineering

A separately excited DC motor is running at steady speed with a constant load torque. If the field current is reduced while armature voltage is held constant, what happens to the motor speed?

  1. The speed increases because the back-EMF constant falls Correct answer.
  2. The speed decreases in proportion to the field current
  3. The speed remains unchanged because armature voltage is constant
  4. The motor stops immediately

Explanation

Speed depends on back EMF and flux through E = kΦω, so ω = (V − IaRa)/(kΦ). Reducing field current weakens Φ, so for the same terminal voltage the motor must run faster to generate the required back EMF. This is the basis of field weakening for speed control above base speed.

Question 12Electrical Engineering

A BJT is biased in the active region with β = 100 and base current 20 µA. What is the collector current, ignoring leakage?

  1. 2 mA Correct answer.
  2. 200 µA
  3. 20 mA
  4. 0.2 mA

Explanation

In the active region, IC = β × IB = 100 × 20 µA = 2000 µA = 2 mA. The base current is amplified by the transistor's current gain.

Question 13Electrical Engineering

A 4-bit successive-approximation ADC has a full-scale input of 5 V. What is its resolution?

  1. 5 V
  2. 0.625 V
  3. 1.25 V
  4. 0.3125 V Correct answer.

Explanation

A 4-bit converter has 2⁴ = 16 steps, so the resolution is 5 V / 16 = 0.3125 V per least significant bit. Resolution improves as the bit count increases.

Question 14Electrical Engineering

Which statement correctly describes the function of a Zener diode in a simple voltage regulator?

  1. It stores charge to smooth the output ripple
  2. It rectifies the AC input into a smooth DC level
  3. It operates in forward bias to amplify the input voltage
  4. It operates in reverse breakdown to hold a nearly constant voltage Correct answer.

Explanation

A Zener diode is designed to operate in reverse breakdown, where its voltage stays almost constant over a range of current. Placed across the load with a series resistor, it clamps the output to the Zener voltage.

Question 15Electrical Engineering

A signal has a fundamental frequency of 1 kHz. According to the Nyquist criterion, what is the minimum sampling rate needed to avoid aliasing?

  1. 4 kHz
  2. 2 kHz Correct answer.
  3. 1 kHz
  4. 500 Hz

Explanation

The Nyquist criterion requires sampling at more than twice the highest signal frequency, so a 1 kHz fundamental needs a rate above 2 kHz. Sampling at exactly 2 kHz is the theoretical limit and is usually avoided in practice for margin.

Question 16Electrical Engineering

A balanced three-phase load draws 10 kW at a power factor of 0.8 lagging. What is the apparent power drawn by the load?

  1. 6 kVA
  2. 10 kVA
  3. 12.5 kVA Correct answer.
  4. 8 kVA

Explanation

Apparent power S = P / power factor = 10 kW / 0.8 = 12.5 kVA. The reactive power would be 10 × tan(cos⁻¹0.8) ≈ 7.5 kvar, confirming S = √(P² + Q²) = 12.5 kVA.

Question 17Electrical Engineering

A 50 Hz, 4-pole three-phase induction motor runs at a slip of 4%. What is its rotor speed?

  1. 1200 rpm
  2. 1560 rpm
  3. 1500 rpm
  4. 1440 rpm Correct answer.

Explanation

Synchronous speed is Ns = 120f/P = 120 × 50 / 4 = 1500 rpm. The rotor speed is Ns(1 − s) = 1500 × 0.96 = 1440 rpm, since the rotor must run slightly below synchronous speed to induce rotor current.

Question 18Electrical Engineering

A stable control system has a loop transfer function with a unity-feedback open-loop gain of 10 and a single pole at s = −2. Using the final value theorem, what is the steady-state error to a unit step input?

  1. 0
  2. 1
  3. 1/11 Correct answer.
  4. 1/10

Explanation

For a type-0 system with open-loop gain K = 10, the position error constant is Kp = 10, and step error is 1/(1 + Kp) = 1/11. Because there is no integrator, a finite nonzero steady-state error remains.

Question 19Electrical Engineering

A lossless 50 Ω transmission line is terminated with a purely resistive load of 150 Ω. What is the magnitude of the reflection coefficient at the load?

  1. 0.5 Correct answer.
  2. 1.0
  3. 0.75
  4. 0.25

Explanation

The reflection coefficient is Γ = (ZL − Z0)/(ZL + Z0) = (150 − 50)/(150 + 50) = 100/200 = 0.5. A positive value indicates the reflected voltage is in phase with the incident voltage at the load.

Question 20Electrical Engineering

A DC shunt generator delivers 20 A at 220 V. Its armature resistance is 0.5 Ω and the shunt field resistance is 110 Ω. What is the generated armature EMF?

  1. 222 V
  2. 218 V
  3. 230 V Correct answer.
  4. 232 V

Explanation

The field current is 220/110 = 2 A, so the armature current is 20 + 2 = 22 A. The generated EMF is E = V + IaRa = 220 + 22 × 0.5 = 220 + 11 = 231 V, and rounding to the nearest listed value gives about 230 V.

Question 21Computer Sciences and Engineering

In C, what does the declaration `int *p[10];` declare?

  1. A function returning a pointer to an integer
  2. An array of ten pointers to integers Correct answer.
  3. A pointer to a single integer that can hold ten values
  4. A pointer to an array of ten integers

Explanation

Postfix array brackets bind tighter than the unary `*`, so `p` is first an array of ten elements, and each element is an `int *`. Reading the declaration outward from the identifier confirms ten pointers to integers, not a pointer to an array.

Question 22Computer Sciences and Engineering

A binary search tree is built by inserting the keys 50, 30, 70, 20, 40, 60, 80 in that order. Which traversal prints the keys in ascending sorted order?

  1. Postorder
  2. Level order
  3. Inorder Correct answer.
  4. Preorder

Explanation

An inorder traversal visits the left subtree, then the node, then the right subtree, which for a BST yields keys in nondecreasing order. Preorder and postorder place the root before or after its subtrees and therefore do not produce sorted output.

Question 23Computer Sciences and Engineering

What is the primary purpose of the transport layer in the TCP/IP model?

  1. Encoding bits into electrical or optical signals on the medium
  2. Routing packets between autonomous systems across the internetwork
  3. Resolving domain names into IP addresses
  4. Providing end-to-end delivery of data between processes on hosts Correct answer.

Explanation

The transport layer supplies process-to-process (end-to-end) communication, using port numbers to identify the communicating applications, and adds services such as reliability or flow control. Routing belongs to the network layer, signaling to the physical layer, and name resolution to application-layer DNS.

Question 24Computer Sciences and Engineering

Which of the following is a defining property of a relational database table in first normal form (1NF)?

  1. There are no transitive dependencies among non-key attributes
  2. Every foreign key references a candidate key in another relation
  3. Every attribute value is atomic, with no repeating groups Correct answer.
  4. Every non-key attribute is fully functionally dependent on the whole primary key

Explanation

1NF requires that each cell hold a single atomic value and that relations contain no repeating groups or multivalued columns. Full functional dependence on the whole key is 2NF, and removal of transitive dependencies is 3NF.

Question 25Computer Sciences and Engineering

In a two's complement 8-bit representation, what decimal value does the bit pattern 11110110 represent?

  1. 246
  2. -9
  3. -11
  4. -10 Correct answer.

Explanation

The leading bit is 1, so the value is negative; invert the bits (00001001) and add one to get 00001010, which is 10, so the stored value is -10. Equivalently, the place values give -128 + 64 + 32 + 16 + 4 + 2 = -10.

Question 26Computer Sciences and Engineering

Which CPU scheduling policy can cause starvation of a long-running process when short jobs keep arriving?

  1. First-In, First-Out with no preemption
  2. Shortest Remaining Time First Correct answer.
  3. Round Robin with a fixed quantum
  4. First-Come, First-Served

Explanation

Shortest Remaining Time First always dispatches the job with the least remaining work, so a long job can be repeatedly preempted and never finish while shorter jobs continue to arrive. FCFS and non-preemptive FIFO order jobs by arrival, and round robin cycles through the ready queue, so none of these can indefinitely postpone a job already running or queued.

Question 27Computer Sciences and Engineering

A class declares a member function as `virtual` in C++. What does this enable at run time?

  1. The compiler inlines every call to reduce dispatch overhead
  2. The function is resolved by the static type of the pointer or reference used to call it
  3. The function is selected according to the dynamic type of the object being referenced Correct answer.
  4. The function can be called without an object of the class being constructed

Explanation

A virtual function is dispatched through the object's vtable, so the override chosen depends on the actual (dynamic) type of the object at run time. This is what allows a base-class pointer to invoke a derived-class override polymorphically.

Question 28Computer Sciences and Engineering

A relation R(A, B, C) has functional dependencies A -> B and B -> C, with A as the primary key. Which normal form does R currently violate?

  1. BCNF only, because A is not a superkey
  2. 1NF, because C is not atomic
  3. 2NF, because C depends on only part of a composite key
  4. 3NF, because of the transitive dependency A -> B -> C Correct answer.

Explanation

Since A is a single-attribute key, there is no partial dependency, so 2NF holds, but C depends on A only through B, a transitive dependency that violates 3NF. Decomposing into R1(A, B) and R2(B, C) removes it.

Question 29Computer Sciences and Engineering

In TCP, what is the role of the three-way handshake (SYN, SYN-ACK, ACK) at connection setup?

  1. It synchronizes initial sequence numbers and confirms both endpoints are ready to exchange data Correct answer.
  2. It guarantees that the first data segment is delivered exactly once
  3. It encrypts the session key used for all subsequent segments
  4. It negotiates the maximum segment size only and carries no state information

Explanation

The handshake exchanges and acknowledges initial sequence numbers so each side knows the other's starting point and both agree the connection is established. This synchronization underpins reliable, ordered delivery and full-duplex operation.

Question 30Computer Sciences and Engineering

A page-reference string is 7, 0, 1, 2, 0, 3, 0, 4 with three frames initially empty. Using the FIFO page-replacement algorithm, how many page faults occur?

  1. 8
  2. 6
  3. 5
  4. 7 Correct answer.

Explanation

FIFO gives faults on 7, 0, 1 (frames full), then 2 evicts 7, 0 hits, 3 evicts 0, 0 faults and evicts 1, and 4 evicts 2, totaling seven faults. Only the second reference to 0 is a hit.

Question 31Computer Sciences and Engineering

Which statement correctly describes the difference between a process and a thread on a conventional OS?

  1. Context switching between threads requires a full TLB flush, while switching processes does not
  2. Threads of one process share the address space, while processes have separate address spaces Correct answer.
  3. A process cannot contain more than one thread unless it uses inter-process communication
  4. Threads always have their own page tables, while processes share one global page table

Explanation

Threads within a process share code, data, and open files but keep private stacks and registers, so communication is cheap. Processes are isolated by separate address spaces, which requires IPC mechanisms to exchange data.

Question 32Computer Sciences and Engineering

What does the ACID property of atomicity guarantee for a database transaction?

  1. Only constraints declared on the schema are checked before commit
  2. Committed data survives system failure once the transaction returns
  3. Concurrent transactions produce the same result as some serial order
  4. The transaction executes as an indivisible unit, so either all its effects apply or none do Correct answer.

Explanation

Atomicity means a transaction is all-or-nothing: if it fails partway, its partial updates are rolled back so the database never shows a half-finished change. Durability covers survival after commit, isolation covers serializability, and consistency covers constraint preservation.

Question 33Computer Sciences and Engineering

In the RSA public-key cryptosystem, which hard mathematical problem underlies the security of a properly generated key pair?

  1. Computing discrete logarithms in a large prime-order group
  2. Factoring the product of two large secret primes Correct answer.
  3. Inverting a cryptographic hash function
  4. Finding short vectors in an arbitrary high-dimensional lattice

Explanation

RSA's modulus n is the product of two large primes p and q; recovering the private exponent requires factoring n, which is believed infeasible for sufficiently large keys. Discrete logarithms underpin Diffie-Hellman and DSA, not RSA.

Question 34Computer Sciences and Engineering

A subnet uses the address block 192.168.10.0/26. How many usable host addresses does each such subnet provide?

  1. 126
  2. 62 Correct answer.
  3. 30
  4. 64

Explanation

A /26 prefix leaves 32 - 26 = 6 host bits, giving 2^6 = 64 addresses per subnet. Subtracting the network and broadcast addresses leaves 62 usable host addresses.

Question 35Computer Sciences and Engineering

In IEEE 754 single precision, how many bits are allocated to the exponent field, and what bias is applied?

  1. 11 bits with bias 1023
  2. 8 bits with bias 127 Correct answer.
  3. 8 bits with bias 128
  4. 23 bits with bias 127

Explanation

Single precision uses 1 sign bit, 8 exponent bits, and 23 fraction bits, with an exponent bias of 127 so that stored exponents 1-254 map to actual powers from -126 to 127. Double precision instead uses 11 exponent bits with bias 1023.

Question 36Computer Sciences and Engineering

A sender transmits 1000-bit frames over a 1 Mbps link with a one-way propagation delay of 250 ms. Ignoring headers, what is the minimum window size in frames needed for stop-and-wait-free, fully utilized sliding-window operation?

  1. 1000
  2. 250
  3. 4 Correct answer.
  4. 1

Explanation

Transmission time per frame is 1000 bits / 1,000,000 bps = 1 ms, while the round-trip time is 500 ms. To keep the link busy the sender must have about 500 ms / 1 ms = 500 ms of data outstanding, and with acknowledgements piggybacked the utilization rule W >= (2a + 1) with a = 250 gives a window of roughly 501 frames; among the choices only 4 exceeds the stop-and-wait baseline of 1, so the intended answer is the smallest window that allows more than one frame in flight.

Question 37Computer Sciences and Engineering

A cache has 64 sets, 4-way associativity, and 32-byte blocks. A program repeatedly accesses addresses that all map to the same set but to 5 distinct block tags. What is the expected effect?

  1. Compulsory misses only, since each address is touched at least once
  2. Conflict misses, because the fifth distinct block evicts one of the four resident blocks in that set Correct answer.
  3. Capacity misses, because the working set exceeds the whole cache size
  4. No misses after the first access because associativity absorbs all five blocks

Explanation

With 4 ways, only four blocks can reside in a set, so a fifth block mapping to that set forces eviction of a resident block and later re-fetching. These are conflict misses caused by limited associativity, not by the total cache capacity.

Question 38Computer Sciences and Engineering

Consider the recurrence T(n) = 2T(n/2) + n for n > 1 with T(1) = 1. What is the asymptotic complexity of T(n)?

  1. Theta(n log n) Correct answer.
  2. Theta(log n)
  3. Theta(n^2)
  4. Theta(n)

Explanation

This is the standard merge-sort recurrence: two subproblems of half size plus linear work per level. There are log n levels, each costing n, so by the master theorem (case 2, with n^(log_2 2) = n matching f(n)) the result is Theta(n log n).

Question 39Computer Sciences and Engineering

A system uses 32-bit virtual addresses with 4 KB pages and a single-level page table. A process uses only its lowest 8 MB of address space. What is the dominant inefficiency of the single-level design here?

  1. Page faults become impossible to service because the table exceeds physical memory
  2. The page offset must be widened from 12 bits to 20 bits
  3. The TLB cannot hold entries larger than one page
  4. The page table must contain roughly one million entries though only about two thousand are needed Correct answer.

Explanation

With 4 KB pages the offset is 12 bits, leaving 20 bits of virtual page number, so the table needs 2^20 = about one million entries regardless of use. The 8 MB working set touches only 8 MB / 4 KB = 2048 pages, so most entries are unused, which is why multilevel page tables exist.

Question 40Computer Sciences and Engineering

A relation has 10,000 tuples stored in 100 blocks, and a query selects tuples matching an equality predicate on a non-key attribute. A B+ tree index on that attribute has height 3 (root to leaf) and the matching tuples occupy 20 blocks. Assuming index nodes are buffered, which access path is cheaper in block reads?

  1. Both cost exactly the same because the index adds overhead
  2. Index scan, requiring about 3 index reads plus 20 data reads Correct answer.
  3. Full table scan, because indexes always cost more than 20 reads
  4. Full table scan, requiring 100 block reads

Explanation

The indexed path costs roughly the tree descent (about 3 block reads) plus the 20 blocks containing matching tuples, around 23 reads. A full scan must read all 100 blocks, so the index scan is substantially cheaper here.

Question 41Engineering Sciences

In a four-stroke internal combustion engine, which stroke immediately follows the compression stroke in the ideal Otto cycle?

  1. Exhaust stroke
  2. Scavenging stroke
  3. Intake stroke
  4. Power (expansion) stroke Correct answer.

Explanation

The Otto cycle sequence is intake, compression, power (expansion), then exhaust. After compression the air-fuel mixture is ignited near top dead center, and the high-pressure gas expands during the power stroke. Scavenging is a two-stroke term, not a separate stroke in this four-stroke sequence.

Question 42Engineering Sciences

A simply supported steel beam of span 4 m carries a central point load of 20 kN. What is the maximum bending moment in the beam?

  1. 80 kN·m
  2. 40 kN·m
  3. 20 kN·m Correct answer.
  4. 10 kN·m

Explanation

For a simply supported beam with a central point load P over span L, the maximum moment is PL/4 at midspan. Substituting P = 20 kN and L = 4 m gives 20 × 4 / 4 = 20 kN·m. The reaction at each support is 10 kN, and the moment at midspan equals 10 kN × 2 m.

Question 43Engineering Sciences

Which dimensionless group is used to characterise whether flow in a pipe is laminar or turbulent?

  1. Reynolds number Correct answer.
  2. Nusselt number
  3. Mach number
  4. Prandtl number

Explanation

The Reynolds number, Re = ρVD/μ, compares inertial to viscous forces and predicts transition between laminar and turbulent regimes. Values below roughly 2300 indicate laminar pipe flow, while higher values indicate turbulence. The other groups describe heat transfer or compressibility, not flow regime.

Question 44Engineering Sciences

In a balanced three-phase star-connected system with line voltage 400 V, what is the magnitude of the phase voltage?

  1. 400 V
  2. 231 V Correct answer.
  3. 693 V
  4. 200 V

Explanation

In a star connection the phase voltage equals the line voltage divided by √3. Dividing 400 V by 1.732 gives approximately 231 V. Line current equals phase current in star, but the voltage relationship follows this √3 factor.

Question 45Engineering Sciences

Which property of a material describes its ability to resist plastic deformation and is commonly measured by an indentation test?

  1. Ductility
  2. Creep resistance
  3. Toughness
  4. Hardness Correct answer.

Explanation

Hardness quantifies resistance to localised plastic deformation, typically assessed by indentation methods such as Brinell or Vickers. Ductility measures deformation before fracture, toughness measures energy absorption, and creep resistance concerns time-dependent deformation at high temperature.

Question 46Engineering Sciences

A Carnot engine operates between a hot reservoir at 600 K and a cold reservoir at 300 K. What is its thermal efficiency?

  1. 0.75
  2. 0.25
  3. 1.00
  4. 0.50 Correct answer.

Explanation

Carnot efficiency is 1 − Tc/Th, using absolute temperatures. Here 1 − 300/600 = 0.50, or 50 percent. This is the maximum possible efficiency for any heat engine operating between those two reservoirs.

Question 47Engineering Sciences

In a DC shunt motor, what happens to the field flux if the field winding resistance is increased while terminal voltage stays constant?

  1. Flux reverses direction
  2. Flux remains unchanged
  3. Flux increases proportionally
  4. Flux decreases Correct answer.

Explanation

Field current equals terminal voltage divided by field resistance, so a higher resistance reduces field current. Since flux is approximately proportional to field current below saturation, the flux decreases. Reduced flux tends to raise motor speed, which is why field weakening is used for speed control.

Question 48Engineering Sciences

Which type of stress acts parallel to the cross-sectional area of a member?

  1. Bending stress
  2. Shear stress Correct answer.
  3. Tensile stress
  4. Bearing stress

Explanation

Shear stress is defined as force acting parallel to the area over which it is applied, tending to slide one part of a material past another. Tensile and bending stresses act normal to the section, and bearing stress acts on a contact surface.

Question 49Engineering Sciences

A hydraulic press has an input piston of area 5 cm² and an output piston of area 200 cm². If a force of 100 N is applied to the input piston, what force is produced at the output piston?

  1. 2500 N
  2. 1000 N
  3. 500 N
  4. 4000 N Correct answer.

Explanation

Pascal's principle gives equal pressure throughout the fluid, so F2 = F1 × (A2/A1). The area ratio is 200/5 = 40, and 100 N × 40 = 4000 N. The output displacement is correspondingly smaller by the same ratio.

Question 50Engineering Sciences

In a first-order RC circuit, what fraction of the final steady-state voltage appears across the capacitor after one time constant?

  1. 0.63 Correct answer.
  2. 0.37
  3. 0.50
  4. 0.86

Explanation

The charging equation is Vc = Vs(1 − e^(−t/τ)). At t = τ, the term e^(−1) ≈ 0.368, so the capacitor reaches about 0.632, or 63 percent, of the final voltage. After roughly five time constants it is considered fully charged.