The energy stored in the magnetic field in a solenoid of length 30cm and diameter 3 cm wound with 1000 turns of wire & carrying a current of 10A is
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The energy stored in the magnetic field in a solenoid of length 30cm and diameter 3 cm wound with 1000 turns of wire & carrying a current of 10A is
A network is said to be linear, if and only if
Kirchoff's law fails in the case of
In a four branch parallel circuit, 50mA current flows in each branch. If one of the branches opens, the current in other branches
The wave length of a wave in a waveguide is
Characteristic impedance of a quarter wave transformer connected in between a load of 100 ohm and a transmission line of characteristic impedance 225 ohms is
A transverse electromagnetic wave with circular polarization is received by a dipole antenna due to polarization mismatch. The power transfer efficiency from the waveto the antenna is reduced to about
The unit of displacement density of a magnetic circuit is
The derivative of an ideal step function is
An impulse function consists of
The discrete time system described by $$y(n) = x(n^2)$$ is
What doesthe transfer function of a system describe for the system?
Which of the following measures cannot be effective in reducing the noise?
Which among the following type of transformer have smallest size with same electrical specification ?
Two transformers operating in parallel will share the load depending upon their ?
Transformer core is laminated,
The eddy current lossesin the transformer will be reduced if ?
The Buchholz relay is used to protect the ?
Why are transformer stamping annealed before being used for the building?
As compared to $$\triangle$$ — $$\triangle$$ bank, the capacity of the V — V bank of transformers is ---- percent.
A transformer on no-load is switched on to a source of voltage. It will draw a current ---
On the twosidesof a star/delta transformer ----
In a Scott-connected transformer the number of primary and teaser turns respectively are ----
The use of higher flux density in the transformer design ---
The applied voltage of a certain transformer is increased by 50% while the frequency is reduced by 50%. The maximum coreflux density will become ---
Power input to a transformer on no-load at rated voltage comprises predominantly of
Distribution transformers have core loss
Non loading heat run test on transformers is performed by means of. -
In power lines, series capacitors are used to----
The starting torque of a slip ring induction motor can be increased by
The synchronous speedof a four-pole induction motor operating at 50Hz is
A shunt generator has a critical field resistance of 200 ohm at a speed of 800r.p.m. If the speed of the generator is increased to 1000r.p.m., what is the change in critical field resistance of the generator?
A three-phase slip ring induction motor is fed from the rotor side with stator winding short circuited. The frequency of currents flowing in short circuited stator is
When the supply voltage to an induction motoris reduced by 10%, the maximum torque decreased by approximately
A 3-phase induction motor is driving full-load torque which is independent of speed. If line voltage drops to 90% of the rated value, percentage increase in motor copper losses
The injected e.m.f in the rotor of an induction motoris of
If the full-load speed of a 3-phase, 50Hz induction motor is 950 r.p.m, what is its half load speed nearly equal to?
For controlling the speed of an induction motor the frequency of supply is increased by 10%. For magnetizing current to remain the same, the supply voltage must
The speed of an induction motoris controlled by varying the supply frequency keeping V/f constant, then
A synchronous generator connected to an infinite bus is overexcited. Consider the only reactive power, from the point of view of the system, the machine acts as
The voltage stress will be maximum in an underground cable at
The dielectric strength of air at a barometric pressure of 76cm and 25 degree centigrade is
The positive sequence current of a transmission line is
For the fault at the terminals of a synchronous generator, the fault current is maximum for a
The earth transformer is used to
For differential protection of power transformer (delta-delta) the current transformers will have
For the protection of a very long extra high voltage line, the protective relay used is
Resistance switching is normally employed in
Symmetrical breaking capacity of ACB is
By which material the fuse element is generally made
Grounding is generally done in transmission line at
What is the approximate value of the surge impedance loading of a 400 kV, 3-phase 50Hz overhead single circuit transmission line
When two identical first order systems have been cascaded non - interactively the unit step response of the system will be
Which of the following methods is most strong tool to determine the Stability and the transient response of the system ?
If the gain of a critically damped system is increased, it will become
Phase margin of a system is used to specify
The rms value of an alternating current is given by steady DC current which when flowing through a given circuit fora given time produces,
AC current cannot be measured directly by
The internal resistance of a voltmeter should be very high in order to have
The resistance of a thermistor
The early effect in a bipolar junction transistor is caused by
Fermi level for an n-type semiconductor lies
For a forward biased pn-junction diode diffusion capacitance varies
In a multi-stage R-C coupled amplifier, the coupling capacitor
An operation amplifier should preferably have
The output voltage of an operational amplifieris ?
A class-A transformer coupled, transistor power amplifier is required to deliver a power output of 10 Watts. The maximum power rating of the transistor should be less than
Which of the following Boolean algebra rules is correct?
In an all NOR gate realization of a combinational circuit all EVEN and ODD level gates behave like
Use of a reverse conducting thyristor in place of antiparallel combination of thyristor and feedback diode in an inverter:
In a resonance pulse inverter:
The vectors $$x_1 = (1, 2, 4), x_2 = (2, -1, 3), x_3 = (0, 1, 2), x_4 = (-3, 7, 2)$$ are
Characteristic roots of matrix $$A$$ and $$A^T$$ will be
The minimum point of the function $$\left(\frac{x^3}{3}\right) - x$$ is at
The area bounded by the curves $$y^2 = 9x, x - y + 2 = 0$$ is given by
The integrating factor of equation $$\sec^2 y \frac{dy}{dx} + x \tan y = x^3$$ is
An urn contains 5 black and 5 white balls. The probability of drawing two balls of the same colour
Ten percent of screws produced in a certain factory turn out to be defective. Find the probability that in a sample of 10 screws chosen at random, exactly two will be defective.
The Equation $$x^3 - x^2 + 4x - 4 = 0$$ is is to be solved using the Newton-Raphson method. If $$x = 2$$ is taken as the initial approximation of the solution, then the next approximation using the method will be
The unique polynomial P(x) of degree 2 such that: P(1) = 1, P(3) = 27, P(4) = 64 is
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