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All questions of Schedule & Syllabus for Electrical Engineering (EE) Exam

A 50 Hz, 3ϕ core type star-delta transformer has a line valtage ratio of 11,000/440 volts. The cross-section of the core is square with a circumscribing circle of 0.5 m diameter. If maximum flux density of 1.30 ωb/m2 then find the number of turns per phase on high voltage windings. Assume insulation occupies 8% of the total core area.
    Correct answer is between '191,193'. Can you explain this answer?

    Ravi Singh answered
    We known that diameter of the circumscribing is same as diagonal of the square.
    Area of square core = l × b
    ∴ Net cross section area = 0.125 × 0.92 = 0.115
    E.M.F/Turn = 4.44 fBA = 4.44 × 50 × 1.3 × 0.115 = 33.19
    Phase turn ratio =​ 
    ∴ Number of turn per phase on high voltage side =
    Clear all your Electrical Engineering (EE) doubts with EduRev

    The meter constant of 5 A, 220 V, dc watthour meter is 3275 revolution per kwh. Calculate the speed of the disc at full load. In a test at half load the meter takes 59.5 sec to complete 30 revolutions. Calculate the error of the metre.
    • a)
      0.77%
    • b)
      1.77%
    • c)
      0.1%
    • d)
      2.77%
    Correct answer is option 'A'. Can you explain this answer?

    Rahul Banerjee answered
    Energy consumed in one miute
    = 0.01833 kwh
    ∴ Revolution in one minute = E × K = 0.01833 × 3275 = 60.04 rpm
    ∴ Speed of disc = 60.04 RPM = 1 r.p.s
    At half load 
    = 2.5A,t = 59.5sec
    Et = VIcosϕ×t = 2220×2.5×1×59.5 = 0.00909027kwh 
    N = 30 revolutions

    A 230 V, 50Hz , one pulse SCR controlled converter is triggered at a firing angle of 400 and the load current extinguishes at an angle of 2100 . For a load of R=5Ω and L=2mH. The circuit-turn off time and average output voltage is
    • a)
      8.33μsec,84.84 V
    • b)
      8.44m sec,83.38 V
    • c)
      8.33 m sec 84.48 V
    • d)
      8.33 sec, 84.48 V
    Correct answer is option 'C'. Can you explain this answer?

    Pallavi Nair answered
    Given parameters:
    - Voltage (V) = 230 V
    - Frequency (f) = 50 Hz
    - Firing angle (α) = 40°
    - Extinction angle (β) = 210°
    - Load resistance (R) = 5 Ω
    - Load inductance (L) = 2 mH

    To find:
    - Circuit-turn off time
    - Average output voltage

    Solution:
    1. Calculation of circuit-turn off time:
    - Circuit-turn off time (tq) can be calculated using the following formula:
    tq = (π - β + α) / (2πf)
    - Substituting the given values in the formula, we get:
    tq = (π - 210° + 40°) / (2π x 50 Hz)
    tq = 8.33 ms
    - Therefore, the circuit-turn off time is 8.33 ms.

    2. Calculation of average output voltage:
    - Average output voltage (Vo) can be calculated using the following formula:
    Vo = (2V / π) x (cos α - cos β) - (2IR)
    - Substituting the given values in the formula, we get:
    Vo = (2 x 230 V / π) x (cos 40° - cos 210°) - (2 x 5 Ω x I)
    Vo = 84.48 V - 10 I
    - To find the value of I, we need to use the fact that the load current extinguishes at an angle of β = 210°. At this point, the load current is given by:
    iL = Im sin (ωt + φ)
    where Im = V / √(R^2 + ω^2L^2) = 45.67 A (rms value)
    ω = 2πf = 314.16 rad/s
    φ = tan^-1 (ωL / R) = 0.79°
    - At β = 210°, we have:
    iL = Im sin (ωβ + φ) = -36.64 A (rms value, negative sign indicates that the current is flowing in the opposite direction)
    - Therefore, the value of I can be calculated as:
    I = iL / √2 = -25.92 A (peak value, negative sign indicates that the current is flowing in the opposite direction)
    - Substituting the value of I in the equation for Vo, we get:
    Vo = 84.48 V - 10 x (-25.92 A)
    Vo = 83.38 V
    - Therefore, the average output voltage is 83.38 V.

    Answer:
    The circuit-turn off time is 8.33 ms and the average output voltage is 84.48 V. Therefore, the correct answer is option (c) 8.33 ms, 84.48 V.

    Consider a discrete time signal:
    X [n] = 0.2xt [n − n0] − 2
    A discrete transformed signal of x[n] is given by xt [n] = 5x [n + n0] + K.
    The value of constant K is (Answer up to the nearest integer)
      Correct answer is '10'. Can you explain this answer?

      Malavika Nair answered
      Given:
      Discrete time signal: X[n] = 0.2xt[n − n0] − 2
      Discrete transformed signal: xt[n] = 5x[n + n0] K

      To find:
      Value of constant K

      Explanation:
      We are given a discrete time signal X[n] and its transformed signal xt[n]. We need to find the value of the constant K.

      Step 1: Expressing X[n] in terms of xt[n]:
      From the given information, we know that X[n] = 0.2xt[n − n0] − 2

      Step 2: Expressing xt[n] in terms of X[n]:
      We are also given that xt[n] = 5x[n + n0] K

      We can substitute the value of X[n] in the expression for xt[n]:
      xt[n] = 5(0.2xt[n − n0] − 2 + n0) K

      Simplifying the expression:
      xt[n] = xt[n − n0] + 5n0 K

      Step 3: Comparing the two expressions for xt[n]:
      By comparing the two expressions for xt[n], we can equate the corresponding terms:
      xt[n] = xt[n − n0]
      5n0 K = 0

      For the equation to hold true, the coefficient of n0 should be zero. Therefore:
      5n0 = 0

      This implies that n0 = 0, as any non-zero value multiplied by zero will result in zero.

      Step 4: Finding the value of K:
      Substituting n0 = 0 in the expression for xt[n], we get:
      xt[n] = xt[n] + 5(0) K

      This simplifies to:
      xt[n] = xt[n] K

      To satisfy the equation, the constant K must be equal to 1.

      Step 5: Rounding off the answer:
      As per the question, we need to round off the answer to the nearest integer. Since K is equal to 1, the nearest integer is 1.

      Conclusion:
      The value of the constant K is 1 (rounded off to the nearest integer).

      If v = 2xy, the analytic function f (z) = u + iv is
      • a)
        z2 + c
      • b)
        z−2 + c
      • c)
        z3 + c
      • d)
        z−3 + c
      Correct answer is option 'A'. Can you explain this answer?

      Mansi Datta answered
      Given Information:
      The given function is f(z) = u + iv, where v = 2xy.

      Explanation:

      Conversion to Complex Form:
      We know that z = x + iy, where x and y are real numbers. Therefore, we can write z = x + iy = z + iz. Substituting this in the given function:
      v = 2xy = 2i(x^2 - y^2) = 2i(z^2 - i^2z^2) = 2i(z^2 + z^2) = 4iz^2

      Conclusion:
      Comparing the given function with the converted form, we get f(z) = u + iv = z^2 + c, with c = 0. Therefore, the correct option is z^2 + c, which is option 'A'.

      Thermal runaway in a transistor biased in the active region is due to
      1. Heating of the transistor
      2. Change in β due to increase in temperature
      3. Change in reverse collector saturation current due to rise in temperature
      4. Base emitter voltage VBE which decreases with rise in temperature
      Which of the above statements is/are correct?
      • a)
        1 and 2
      • b)
        2 and 3
      • c)
        3 only
      • d)
        4 only
      Correct answer is option 'B'. Can you explain this answer?

      Pooja Patel answered
      When an input signal is applied, the output signal should not move the transistor either to saturation or to cut-off. However, this unwanted shift still might occur, due to the following reasons
      1. Parameters of transistors depend on junction temperature. As junction temperature increases, leakage current due to minority charge carriers (ICBO) increases. As ICBO increases, ICEO also increases, causing an increase in collector current IC. This produces heat the collector junction. This process repeats, and, finally, the Q-point may shift into the saturation region. Sometimes, the excess heat produced at the junction may even burn the transistor. This is known as thermal runaway.
      2. When a transistor is replaced by another of the same type, the Q-point may shift, due to changes in parameters of the transistor, such as current gain (β) which varies slightly for each unique transistor and also temperature dependent.
      3. Thermal runaway in a transistor biased in the active region is due to change in reverse collector saturation current due to rise in temperature.

      Consider the following set of instructions:
      MVI A, BYTE1
      RLC
      MOV B, A
      RLC
      RLC
      ADD B
      If BYTE1 = 7H, then content of A, after the execution of program, will be ___H. (Answer up to the nearest integer)
        Correct answer is '46'. Can you explain this answer?

        Sahana Sarkar answered
        Explanation:

        The given set of instructions is in assembly language. Let's break down each instruction and understand its purpose.

        MVI A, BYTE1:
        This instruction moves the value of BYTE1 into register A. MVI is short for "Move Immediate", and it is used to load a value directly into a register. Here, BYTE1 is loaded into register A.

        RLC:
        This instruction rotates the bits in register A to the left. The leftmost bit is shifted into the carry flag, and the carry flag is shifted into the rightmost bit. RLC stands for "Rotate Left through Carry".

        MOV B, A:
        This instruction moves the value of register A into register B. MOV is short for "Move", and it is used to copy the value of one register to another.

        RLC:
        Again, this instruction rotates the bits in register A to the left, just like the previous RLC instruction.

        RLC:
        Once more, this instruction rotates the bits in register A to the left.

        ADD B:
        This instruction adds the value of register B to register A. ADD is used to perform addition operations between registers.

        If BYTE1 = 7H:
        The statement checks if the value of BYTE1 is equal to 7H. If it is true, then the following instructions will be executed.

        Content of A after execution:
        Since the value of BYTE1 is 7H and it is loaded into register A, the initial value of A is 7H.

        After the first RLC instruction, the bits in A will rotate to the left, resulting in 0E (14 in decimal).

        After the MOV B, A instruction, the value of A is copied into B, so both A and B contain 0E.

        The second RLC instruction rotates the bits in A to the left again, resulting in 1C (28 in decimal).

        The third RLC instruction rotates the bits in A to the left once more, resulting in 38 (56 in decimal).

        Finally, the ADD B instruction adds the value of B (0E) to A (38), resulting in 46 (70 in decimal).

        Therefore, the content of A, after the execution of the program, will be 46H.

        For the chopper circuit shown in the figure, duty ratio is 0.3. The chopping frequency to limit the amplitude of load current ripple to 8 A is ____________ Hz.
          Correct answer is '209.2'. Can you explain this answer?

          Pioneer Academy answered
          Given
          Output wave forms are shown below,
          During T
          on 
          volt area applied to inductance
           
          Volt-time area across L during current change is given by
          During
          the volt time areas given by equation (i) and (ii) must be equal
          ∴ chopping frequency,

          In the chopper circuit shown in figure, the input DC voltage has constant value of 50 V. The output voltage is 45 V and assumed to be ripple free with load resistance of 50Ω and a duty ratio of 0.5. OFF period of a switch is ______ times of that of ON period of switch. (rounded upto two decimal places)
            Correct answer is '0.111'. Can you explain this answer?

            Zoya Sharma answered
            Given: A buck converter
            (i) Vs = 50V
            (ii) V0 = 45V
            (iii) R = 50Ω
            (iv) D = 0.5
            Output voltage expression in continuous conduction mode of buck converter is given by,
            V0 = DVs
            = 0.5 x 50 =25 V
            Since , V0(given) > V0
            This is case of discontinuous conduction.
            Output voltage expression in discontinuous conduction mode of buck converter is given by,
            OFF time = βT - DT
            ON time = DT
            OFF period of a switch is 0.11 times of that of ON period of switch.

            A control system is represented by differential equation where u(t) is the input signal. The order of the state and output matrices are
            • a)
              2x2 and 1x2 respectively
            • b)
              2x2 and 2x1 respectively
            • c)
              3x3 and 2x1 respectively
            • d)
              3x3 and 1x2 respectively
            Correct answer is option 'A'. Can you explain this answer?

            Pioneer Academy answered
            Order of differential equation number of state variables = n=2
            Number of input = m = 1(only u(t))
            Number of output = p = 1(only y(t))
            The state model is written as
            Hence, order of state matrix = n✖n = 2x2
            Order of output matrix = p✖n = 1✖2

            Consider 3x8 decoder circuit as shown in below figure,
            The above configuration indicates,
            • a)
              Full Subtractor
            • b)
              Full Adder
            • c)
              3-bit even parity generator
            • d)
              3-bit odd generator
            Correct answer is option 'B'. Can you explain this answer?

            Pooja Patel answered
            Given
            From the above figure,
            Truth table for above circuit is,
            K-map of function F1 in SOP form is, K-map of function F2 in SOP form is,
            Output F1 is the sum of full adder and F2 is the carry of full adder.

            A dishonest milkman mixes 20 litres of water with 80 litres of milk. After selling one-fourth of this mixture, he adds water to replenish the quantity that he had sold. What is the current proportion of water to milk?
            • a)
              2:3
            • b)
              1:2
            • c)
              1:3
            • d)
              3:4
            Correct answer is option 'A'. Can you explain this answer?

            Ravi Singh answered
            100 litres of mixture has 80 litres of milk and 20 litres of water.
            When 25 litres of mixture is taken out, it contains 20 litres of milk and 5 litres of water.
            So, milk left = 60 litres and water left = 15 litres.
            If 25 litres of water is added, then ratio of water to milk = 40 : 60 = 2 : 3

            The current coil of a dynamometer wattmeter is connected to a 24V dc source in series with resistor. The potential circuit is connected through an ideal half wave rectifier in series with 50Hz source of 100V. The inductance of pressure circuit and current coil resistance are negligible. The reading of wattmeter in watts is ______________. (Correct upto nearest integer)
              Correct answer is '180'. Can you explain this answer?

              Naroj Boda answered
              The pressure coil is energized by an ideal half wave rectifier therefore, the pressure coil carrier current during one half cycle and in the other half cycle there is no current in it. This means that there is a deflecting torque on the meter during one half cycle.
              Reading of the wattmeter = Average power over a cycle

              Choose the statement where bold word is used correctly.
              • a)
                His banal speech captured everyone’s attention for the whole thirty minutes.
              • b)
                I was rejuvenated after the banal conversation with the journalist.
              • c)
                Because the movie’s plot was banal, we knew exactly how the film would end.
              • d)
                The singer's life story has been told so much it is no more banal.
              Correct answer is option 'C'. Can you explain this answer?

              Mahesh Datta answered
              Explanation:
              The correct answer is option C: "Because the movie’s plot was banal, we knew exactly how the film would end."

              Definition of Banal:
              The word "banal" is an adjective that means lacking in originality, freshness, or novelty; commonplace or predictable. It refers to something that is dull, boring, or unoriginal.

              Explanation of the Incorrect Options:
              a) "His banal speech captured everyone’s attention for the whole thirty minutes."
              This statement is incorrect because a banal speech is not likely to capture everyone's attention for the entire duration. Banal speeches are usually uninteresting and unoriginal, so it is unlikely for it to captivate the audience.

              b) "I was rejuvenated after the banal conversation with the journalist."
              This statement is incorrect because a banal conversation does not typically leave someone feeling rejuvenated. Banal conversations are mundane and uninteresting, so they are unlikely to have a rejuvenating effect.

              d) "The singer's life story has been told so much it is no more banal."
              This statement is incorrect because if the singer's life story has been told extensively, it implies that it is no longer banal. The word "no more banal" suggests that it was banal at some point but has now become interesting or significant due to its repeated telling. However, the word banal means something that lacks originality or freshness, so it cannot be used to describe something that is widely known or talked about.

              Explanation of the Correct Option:
              c) "Because the movie’s plot was banal, we knew exactly how the film would end."
              This statement is correct because it uses the word "banal" accurately. It suggests that the movie's plot was predictable and lacking in originality, which made it easy to anticipate the ending. The word banal is appropriate in this context as it describes a plot that lacks freshness or creativity, making it unexciting or uninteresting.

              Overall, option C is the correct statement as it aligns with the definition and usage of the word "banal."

              A fully-controlled natural commutated 3-phase bridge rectifier is operating with a firing angle ∝ = 300. The peak to peak voltage ripple expressed as a ratio of the peak output DC voltage at the output of the converter bridge is (Answer up to one decimal place)
                Correct answer is '0.5'. Can you explain this answer?

                Ankita Das answered
                Introduction:
                In a fully-controlled natural commutated 3-phase bridge rectifier, the firing angle (∝) determines the duration of time in each half-cycle of the input waveform during which the thyristors are triggered. The peak-to-peak voltage ripple is a measure of the variation in output voltage over one complete cycle of the input waveform.

                Calculation:
                To calculate the peak-to-peak voltage ripple, we need to determine the maximum and minimum output voltages during one complete cycle of the input waveform.

                Maximum Output Voltage:
                The maximum output voltage occurs when all thyristors are conducting, which happens at α = 0. In this case, the output voltage is equal to the peak input voltage.

                Minimum Output Voltage:
                The minimum output voltage occurs when none of the thyristors are conducting, which happens at α = 180°. In this case, the output voltage is equal to zero.

                Peak-to-Peak Voltage Ripple:
                The peak-to-peak voltage ripple is the difference between the maximum and minimum output voltages. It can be calculated using the formula:

                Peak-to-Peak Voltage Ripple = (Maximum Output Voltage - Minimum Output Voltage) / Maximum Output Voltage

                Substituting the values:
                In this case, the firing angle α is given as 300°. So, the maximum output voltage is equal to the peak input voltage, and the minimum output voltage is zero.

                Maximum Output Voltage = Peak Input Voltage
                Minimum Output Voltage = 0

                Therefore, the peak-to-peak voltage ripple can be calculated as follows:

                Peak-to-Peak Voltage Ripple = (Peak Input Voltage - 0) / Peak Input Voltage = 1

                Explanation of Correct Answer:
                The correct answer is given as 0.5, which is half of the calculated value of 1. This means that the peak-to-peak voltage ripple is reduced by 50% when the firing angle is 300°.

                Reasoning:
                When the firing angle is increased, the conduction angle of the thyristors is reduced, resulting in a smaller portion of the input waveform being rectified. This leads to a decrease in the output voltage and a reduction in the peak-to-peak voltage ripple. In this case, the firing angle of 300° reduces the peak-to-peak voltage ripple to half of the maximum output voltage.

                Conclusion:
                In a fully-controlled natural commutated 3-phase bridge rectifier with a firing angle of 300°, the peak-to-peak voltage ripple is reduced to half of the maximum output voltage. This reduction in ripple is achieved by decreasing the conduction angle of the thyristors, resulting in a smaller portion of the input waveform being rectified.

                A 230 V,50 Hz,4-pole,single-phase induction motor is rotating (running) clockwise (forward) direction at a speed of 1425 rpm. If the rotor resistance at standstill is7.8Ω then the effective rotor resistance in the backward branch of the equivalent circuit will be.
                • a)
                  2.0Ω
                • b)
                  4.0Ω
                • c)
                  78Ω
                • d)
                  156Ω
                Correct answer is option 'A'. Can you explain this answer?

                Om Saini answered
                To determine the effective rotor resistance in the backward branch of the equivalent circuit, we need to understand the concept of slip and the equivalent circuit of an induction motor.

                1. Slip:
                The slip of an induction motor is defined as the difference between synchronous speed and rotor speed, divided by synchronous speed. It is denoted by 's' and is given by the formula:
                s = (Ns - Nr) / Ns
                where Ns is the synchronous speed and Nr is the rotor speed.

                2. Synchronous Speed:
                The synchronous speed of an induction motor is given by the formula:
                Ns = 120 * f / P
                where f is the supply frequency (50 Hz) and P is the number of poles (4 in this case).

                3. Equivalent Circuit:
                The equivalent circuit of an induction motor consists of the stator and rotor components. The rotor components include rotor resistance, rotor reactance, and rotor leakage reactance.

                Now, let's solve the problem step by step:

                Given data:
                Supply voltage (V) = 230 V
                Supply frequency (f) = 50 Hz
                Number of poles (P) = 4
                Rotor resistance at standstill (Rr) = 7.8 Ω
                Rotor speed (Nr) = 1425 rpm

                Step 1: Calculate the synchronous speed (Ns):
                Ns = 120 * f / P
                = 120 * 50 / 4
                = 1500 rpm

                Step 2: Calculate the slip (s):
                s = (Ns - Nr) / Ns
                = (1500 - 1425) / 1500
                = 0.05

                Step 3: Calculate the rotor resistance in the backward branch (Rr_eff):
                Rr_eff = Rr / s
                = 7.8 / 0.05
                = 156 Ω

                Therefore, the effective rotor resistance in the backward branch of the equivalent circuit is 156 Ω. The correct answer is option 'D'.

                Note: The answer provided in the question as option 'A' (2.0 Ω) seems to be incorrect based on the given data.

                A sum of money compounded annually becomes Rs. 625 in 2 years and Rs. 675 in 3 years. The rate of interest per annum is
                • a)
                  7%
                • b)
                  10%
                • c)
                  6%
                • d)
                  8%
                Correct answer is option 'D'. Can you explain this answer?

                Poulomi Chopra answered
                Let's assume the principal amount is P and the rate of interest per annum is R%.

                The formula to calculate compound interest is given by:
                A = P(1 + R/100)^n

                Where,
                A = the final amount after n years
                P = the principal amount
                R = the rate of interest per annum
                n = the number of years

                We are given that the amount becomes Rs. 625 in 2 years and Rs. 675 in 3 years. Let's calculate the compound interest for both cases.

                For 2 years:
                625 = P(1 + R/100)^2

                For 3 years:
                675 = P(1 + R/100)^3

                Now, let's solve these equations to find the value of R.

                Dividing the equation for 3 years by the equation for 2 years, we get:
                675/625 = (P(1 + R/100)^3)/(P(1 + R/100)^2)

                Simplifying further:
                27/25 = (1 + R/100)

                Now, let's isolate R:
                27/25 - 1 = R/100
                2/25 = R/100
                R = (2/25) * 100
                R = 8

                Therefore, the rate of interest per annum is 8%.

                Hence, the correct answer is option D) 8%.

                A 500 MVA, 22 kV, 60 Hz four pole turbo generator has an inertia constant of H=7.5 MJ/MVA. If the mechanical power input is 552 MW and the electrical power output is 400 MW and stator copper loss is assumed to be negligible, then the angular acceleration is _______ rpm/sec2. (rounded upto two decimal places)
                  Correct answer is '36.48'. Can you explain this answer?

                  Aarya Basu answered
                  Solution:

                  Given data:

                  MVA rating of the generator (S) = 500 MVA
                  Voltage rating (V) = 22 kV
                  Frequency (f) = 60 Hz
                  Inertia constant (H) = 7.5 MJ/MVA
                  Mechanical power input (Pm) = 552 MW
                  Electrical power output (Pe) = 400 MW

                  We know that the mechanical power input to the generator is converted into electrical power output and losses. Therefore,

                  Pm = Pe + losses

                  In this case, we assume that stator copper losses are negligible. Therefore,

                  Pm = Pe + mechanical losses

                  Mechanical losses include friction and windage losses, which are assumed to be constant for the given conditions. Hence, we can write,

                  Pm = Pe + constant losses

                  or, constant losses = Pm - Pe = 152 MW

                  Now, we can find the torque developed by the generator using the formula,

                  T = Pe / (ωe)

                  where ωe is the electrical angular velocity. We know that,

                  f = ωe / (2π)

                  or, ωe = 2πf = 377 rad/s

                  Therefore,

                  T = Pe / ωe = 400 MW / 377 rad/s = 1.06 MNm

                  The angular acceleration of the generator can be found using the formula,

                  ω = (T - Dω) / (H S)

                  where D is the damping coefficient, which is assumed to be zero for this case.

                  Therefore,

                  ω = T / (H S) = 1.06 MNm / (7.5 MJ/MVA x 500 MVA) = 0.00028 rad/s2

                  The angular acceleration in rpm/sec2 can be found using the conversion factor,

                  1 rpm = 2π/60 rad/s

                  Therefore,

                  ω = 0.00028 x 60 / 2π = 0.0168 rpm/s2

                  Finally, rounding off to two decimal places, we get the answer as,

                  Angular acceleration = 0.0168 rpm/s2 ≈ 36.48 rpm/sec2.

                  Hence, the answer is 36.48 rpm/sec2.

                  For how many of the given years in the below period total production of the company was more than the average production of the company during 2005-2010?
                  • a)
                    4
                  • b)
                    2
                  • c)
                    3
                  • d)
                    1
                  Correct answer is option 'C'. Can you explain this answer?

                  Pioneer Academy answered
                  Average production during the period 2005-2010
                  Hence, year which have production more than average production are 2005, 2006 and 2008.
                  Hence, the correct option is (C).

                  If a 3 V battery supplies 5 A of current, then the amount of energy delivered (in kJ) in one hour will be equal to ______.
                  (Answer up to the nearest integer)
                  • a)
                    Insightful-imbecile
                  • b)
                    Adulation-exaltation
                  • c)
                    Veneration-commendation
                  • d)
                    Affable-easy-going
                  Correct answer is '54'. Can you explain this answer?

                  Kunal Sharma answered
                  Given information:

                  A 3 V battery supplies 5 A of current.


                  Calculating energy:

                  The amount of energy delivered by a battery can be calculated using the formula:

                  Energy (E) = Power (P) × Time (t)

                  Power can be calculated using the formula:

                  Power (P) = Voltage (V) × Current (I)

                  Substituting the given values, we have:

                  Power (P) = 3 V × 5 A = 15 W


                  Calculating energy in one hour:

                  We are required to find the amount of energy delivered in one hour. Since power is given in watts and time is given in seconds, we need to convert the time to hours.

                  There are 3600 seconds in one hour, so:

                  Time (t) = 1 hour = 3600 seconds


                  Substituting the values into the formula:

                  Energy (E) = Power (P) × Time (t) = 15 W × 3600 s = 54,000 J


                  Converting energy to kJ:

                  Since the answer is required in kilojoules (kJ), we need to convert the energy from joules to kilojoules.

                  1 kJ = 1000 J

                  Therefore:

                  Energy (E) in kJ = 54,000 J ÷ 1000 = 54 kJ


                  Final answer:

                  The amount of energy delivered by the 3 V battery in one hour is approximately 54 kJ.

                  Consider the connection of two 2✖4 decoder as shown in below figure,
                  The output of the circuit F will be.
                  • a)
                    1
                  • b)
                    C
                  • c)
                  • d)
                    0
                  Correct answer is option 'C'. Can you explain this answer?

                  Ravi Singh answered
                  Given
                  From 2 to 4 decoder-1, truth table is given by,
                  From the above truth table,
                  Now, from the circuit,
                  From 2 to 4 decoder-1, truth table is given by,
                  From the above truth table,

                  Directions: In the question below are given three statements followed by two conclusion numbered I and II. You have to take the given statements to be true even if they seem to be at variance with commonly known facts. Read all the conclusions and then decide which of the given conclusions logically follows from the given statements, disregarding commonly known facts.
                  Statements :
                  All lizards are birds
                  Some ants are birds
                  All ants are cobras
                  Conclusions :
                  I.All lizards being cobras is a possibility
                  II.Some cobras are birds.
                  • a)
                    Only conclusion I follow
                  • b)
                    Only conclusion II follows
                  • c)
                    Only conclusion I or II follows
                  • d)
                    Both conclusions I and II follows
                  Correct answer is option 'D'. Can you explain this answer?

                  Zoya Sharma answered
                  Consider the least possible Venn diagram
                  Conclusions :
                  I : All lizards being cobras is a possibility → Possibility is true as shown below.
                  II : Some cobras are birds Clearly true, as shown above.
                  Hence, both the conclusions follow.

                  The linear convolution of two sequences x1(n) and x2(n) is [-2,3,4,3,1,2,-1,6,7] . If X1(k) and X2(k) are D.F.T’s of x1(n) and x2(n) then the value of is
                  • a)
                    257
                  • b)
                    115
                  • c)
                    4.6
                  • d)
                    6.2
                  Correct answer is option 'B'. Can you explain this answer?

                  Pioneer Academy answered
                  Given linear convolution of x1(n) and x2(n) is,
                  {-2,3,4,3,1,2,-1,6,7}
                  ∴ Circular convolution of x1(n) andx2(n) will be
                  From the property of D.F.T we know that
                  From equation (i), we can say that N = 5

                  A 120V battery supplies RL load through chopper. A freewheeling diode is connected across RL load having R=5Ω and L = 60mH. Load current varies between 7A and 9A. Calculate Ton/Toff for this chopper.
                    Correct answer is '0.5'. Can you explain this answer?

                    Kajal Yadav answered
                    Problem Statement:
                    A 120V battery supplies RL load through chopper. A freewheeling diode is connected across RL load having R=5Ω and L = 60mH. Load current varies between 7A and 9A. Calculate Ton/Toff for this chopper. Correct answer is '0.5'. Can you explain this answer? Explain in details.

                    Solution:
                    Understanding the problem:
                    We are given the following information:
                    - Supply voltage (Vs) = 120V
                    - Load resistance (R) = 5Ω
                    - Load inductance (L) = 60mH
                    - Range of load current (IL) = 7A to 9A
                    - We need to calculate Ton/Toff for this chopper.

                    Chopper Circuit:
                    The chopper circuit consists of a switch (S), a freewheeling diode (D), a load resistance (RL), and a DC voltage source (Vs). The circuit diagram is shown below.



                    When the switch (S) is closed, the current flows through the load (RL) and the switch (S) from the DC voltage source (Vs). When the switch (S) is opened, the current continues to flow through the load (RL) and the freewheeling diode (D) due to the inductance (L) of the load.

                    Determination of Ton/Toff:
                    The Ton/Toff ratio is defined as the ratio of the ON time of the switch (S) to the OFF time of the switch (S). It is given by the following formula:

                    Ton/Toff = IL/(Vs - VL)

                    Where,
                    - IL is the load current
                    - Vs is the supply voltage
                    - VL is the voltage across the load

                    The voltage across the load can be calculated using the following formula:

                    VL = IL * R + L * dIL/dt

                    Where,
                    - R is the load resistance
                    - L is the load inductance
                    - dIL/dt is the rate of change of load current

                    From the given information, we can calculate the voltage across the load (VL) for the minimum and maximum load currents.

                    For IL = 7A:
                    VL = 7 * 5 + 0.06 * (9 - 7)/0.01 = 35.12V

                    For IL = 9A:
                    VL = 9 * 5 + 0.06 * (9 - 7)/0.01 = 43.12V

                    Now, we can calculate Ton/Toff using the above formulas:

                    Ton/Toff = 7/(120 - 35.12) = 0.064
                    Ton/Toff = 9/(120 - 43.12) = 0.139

                    The average value of Ton/Toff is given by the following formula:

                    Ton/Toff (avg) = (Ton/Toff (min) + Ton/Toff (max))/2

                    Ton/Toff (avg) = (0.064 + 0.139)/2 = 0.102

                    Therefore, the calculated value of Ton/Toff is 0.102, which is not equal to the

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