If resistance is 8 Ohm and current is 16 ampere then what will be the voltage and power?

128 volts ,2048 watts

asked
Oct 21, 2017
by
anonymous

A d.c. voltage of 230 V is imposed on an unloaded 230 V, 50 Hz transformer, it will (A) give high secondary voltage (B) burn out (C) give secondary voltage as per k (D) None of these

A d.c. voltage of 230 V is imposed on an unloaded 230 V, 50 Hz transformer, it will burn out

asked
May 13, 2018
by
anonymous

A single phase 230 V/ 150 V , 1 kVA, 50 Hz transformer is supplied by 230 V AC supply. Find the full load primary and secondary current.

asked
Sep 1, 2018
by
anonymous

lf slip of an induction machine is 0.02 and the stator supply frequency is 50 Hz, what will be the frequency of the rotor induced e.m.f.? (A) 10 Hz (B) 50 Hz (C) 1 Hz (D) 2500 Hz

1hz

asked
Apr 9, 2018
by
anonymous

what will be the capacitance if three capacitors connected in parallel each having value of 0.5 micro Farad ?

the total capacitace when connected in parallel Tc=total capacitor c1=c2=c3=0.5uf Tc=c1+c2+c3 Tc=1.5uf

asked
Dec 11, 2017
by
anonymous

Upload failed: [object Object]

asked
Oct 14, 2020
by
anonymous

If an incandescent lamp of 80 ohms resistance takes a current of 0.75 ampere, what voltage is required to light it? A.45 volts B.60 volts c.23 volts D.None of these

V=IR = 80*0.75 = 60 volts

asked
May 15, 2018
by
anonymous

A transformer at 25 Hz develops 20 W hysteresis loss and 50 W eddy current loss. If the applied voltage and frequency are doubled, the new core losses are (A) 140 W (B) 180 W (C) 240 W (D) 480 W

A transformer at 25 Hz develops 20 W hysteresis loss and 50 W eddy current loss. If the applied voltage and frequency are doubled, the new core losses are 240 W

asked
Apr 28, 2018
by
anonymous

The low voltage winding of a 400/230 V, 1-phase, 50 Hz transformer is to be connected to a 25 Hz, the supply voltage should be

The low voltage winding of a 400/230 V, 1-phase, 50 Hz transformer is to be connected to a 25 Hz, the supply voltage should be 115 V.

asked
Mar 27, 2018
by
anonymous

The locked rotor current in a 3-phase, star connected 15 , kW 4 , pole 230 V , 50 Hz induction motor at rated conditions is 50 A. Neglecting losses and magnetizing current, the approximate locked rotor line current drawn when the motor is connected to a 236 , V 57 Hz supply is (A) 58.5 A (B) 45.0 A (C) 42.7 A (D) 55.6 A

The locked rotor current in a 3-phase, star connected 15 , kW 4 , pole 230 V , 50 Hz induction motor at rated conditions is 50 A. Neglecting losses and magnetizing current, the approximate locked rotor line current drawn when the motor is connected to a 236 , V 57 Hz supply is 45.0 A

asked
May 17, 2018
by
anonymous

A 3 phase, 400 volts, 50 Hz, 100 kW, 4 pole squirrel cage induction motor with a rated slip of 2% will have a rotor speed of: (A) 1500 rpm (B) 1470 rpm (C) 1530 rpm (D) 1570 rpm

1470rpm

asked
Apr 11, 2018
by
anonymous

Sinusoids find amplitude, period, frequency, voltage (Problem 1)

Sinusoids find amplitude, period, frequency, voltage (Problem 1)

asked
Mar 29, 2020
by
anonymous

The reactance offered by a capacitor to an alternating current of frequency 50 Hz is 10 ohm. If frequency is increased to 100 Hz, the reactance will be (a) 2.5 ohm (b) 5.0 ohm (c) 20.0 ohm (d) 40.0 ohm

Xc = 1/(2*pi*f*c) so when f is double .... Xc will be half ... Ans is 5ohm

asked
May 25, 2018
by
anonymous

What would happen if a power transformer designed for operation on 50 Hz (frequency) were connected to a 500 Hz (frequency) source of the same voltage: (A) Eddy Current and Hysteresis losses will be excessive (B) Current will be too much high (C) Transformer may start to smoke and burn (D) No effect

What would happen if a power transformer designed for operation on 50 Hz (frequency) were connected to a 500 Hz (frequency) source of the same voltage: (A) Eddy Current and Hysteresis losses will be ... will be too much high (C) Transformer may start to smoke and burn (D) No effect

asked
May 8, 2018
by
anonymous

For a 500 Hz frequency excitation, a 50 km long power line will be modeled as

For a 500 Hz frequency excitation, a 50 km long power line will be modeled as long line

asked
Apr 29, 2018
by
anonymous

The reactance offered by a capacitor to alternating current of frequency 50 Hz is 20 Q. If frequency is increased to 100 Hz, reactance becomes_____ohms.

The reactance offered by a capacitor to alternating current of frequency 50 Hz is 20 Q. If frequency is increased to 100 Hz, reactance becomes 10 ohms.

asked
Mar 24, 2018
by
anonymous

If 1 ampere current is flowing through a 100 mH coil, then energy stored in the coil is (a) 0.05 Joules (b) 0.5 Joules (c) 5.0 Joules (d) None of these

asked
May 25, 2018
by
anonymous

Problem on resistance and resistivity 1

Problem on resistance and resistivity 1

asked
May 16, 2019
by
anonymous

The eddy current loss in an AC motor is 100 watts at 50 Hz. Its losses at 100 Hz will be: (A) 25 watts (B) 59 watts (C) 100 watts (D) 400 watts

The eddy current loss in an AC motor is 100 watts at 50 Hz. Its losses at 100 Hz will be: 400 watts

asked
Apr 11, 2018
by
anonymous

If a capacitance is charged by a square wave current source, then the voltage across the capacitor will be (a) Square wave (b) Step function (c) Triangular wave (d) Zero

If a capacitor is charged by a square wave current source, the voltage across the capacitor is : triangular wave

asked
May 25, 2018
by
anonymous

The frequency of direct current is _______ (1) Zero (2) 50 HZ (3) 60 HZ (4) 100 HZ

Zero

asked
Jan 22
by
anonymous

In a 230 V, 50 Hz single-phase SCR bridge converter operating at a firing delay angle, α and with large R-L load, the input source current is (A) sinusoidal current (B) constant dc current (C) continuous rectangular pulses (D) alternating rectangular pulses

In a 230 V, 50 Hz single-phase SCR bridge converter operating at a firing delay angle, α and with large R-L load, the input source current is alternating rectangular pulses

asked
Apr 28, 2018
by
anonymous

Problem on resistance and resistivity 13

Problem on resistance and resistivity 13

asked
May 19, 2019
by
anonymous

Problem on resistance and resistivity 12

Problem on resistance and resistivity 12

asked
May 19, 2019
by
anonymous

Problem on resistance and resistivity 11

Problem on resistance and resistivity 11

asked
May 19, 2019
by
anonymous

Problem on resistance and resistivity 10

Problem on resistance and resistivity 10

asked
May 19, 2019
by
anonymous

Problem on resistance and resistivity 9

Problem on resistance and resistivity 9

asked
May 19, 2019
by
anonymous

Problem on resistance and resistivity 8

Problem on resistance and resistivity 8

asked
May 18, 2019
by
anonymous

Problem on resistance and resistivity 7

Problem on resistance and resistivity 7

asked
May 18, 2019
by
anonymous

Problem on resistance and resistivity 6

Problem on resistance and resistivity 6

asked
May 18, 2019
by
anonymous

Problem on resistance and resistivity 5

Problem on resistance and resistivity 5

asked
May 18, 2019
by
anonymous

Problem on resistance and resistivity 4

Problem on resistance and resistivity 4

asked
May 18, 2019
by
anonymous

Problem on resistance and resistivity 3

Problem on resistance and resistivity 3

asked
May 18, 2019
by
anonymous

Problem on resistance and resistivity 2

Problem on resistance and resistivity 2

asked
May 18, 2019
by
anonymous

A single-phase, 230 V, 50 Hz ac mains fed step down transformer (4:1) is supplying power to a half-wave uncontrolled ac-dc converter used for charging a battery (12 V dc) with the series current limiting resistor being 19.04 Ohm. The charging current is (A) 2.43 A (B) 1.65 A (C) 1.22 A (D) 1.0 A

A single-phase, 230 V, 50 Hz ac mains fed step down transformer (4:1) is supplying power to a half-wave uncontrolled ac-dc converter used for charging a battery (12 V dc) with the series current limiting resistor being 19.04 Ohm. The charging current is 1.0 A

asked
May 18, 2018
by
anonymous

Problem on temperature coefficient of resistance 1

Problem on temperature coefficient of resistance 1

asked
May 19, 2019
by
anonymous

If resistance is 20 Q. and inductance is 27 in a R-L series circuit, then time constant of this circuit will be?

0.1s

asked
Mar 25, 2018
by
anonymous

A 230 V, 50 Hz phase controlled single-phase full-controlled SCR bridge converter draws 15 A constant dc current. If the source inductance is 3 mH, the drop in dc output voltage is (A) 4.5 V (B) 6.75 V (C) 9 V (D) 13.5 V

A 230 V, 50 Hz phase controlled single-phase full-controlled SCR bridge converter draws 15 A constant dc current. If the source inductance is 3 mH, the drop in dc output voltage is 9 V

asked
Apr 28, 2018
by
anonymous

If the phase difference between two points is 120° for a wave with velocity of 360 m/ and frequency 500 Hz, then path difference between the two points is (1) 1 cm (2) 6 cm (3) 12 cm (4) 24 cm

24 cm

asked
Jan 21
by
anonymous

Problem on temperature coefficient of resistance 3

Problem on temperature coefficient of resistance 3

asked
May 20, 2019
by
anonymous

Problem on temperature coefficient of resistance 2

Problem on temperature coefficient of resistance 2

asked
May 20, 2019
by
anonymous

There is a bridge besides a river. Two friends Arun and varun started their journey from place L, moved to the garden located at another place M & then returned to place L. Arun moves by swimming at a speed of 30 km/hr while Varun sails on a boat at a speed of about 24km/hr. If the flow of water current is at the speed of 12km/hr, what will be the average speed of boat sailor? A) 36 B) 18 C) 24 D) 48

ANSWER:B Explanation: As Arun swims both the ways at the speed of 30km/hr, the average speed of swimming is 30 km/hr Being a boat sailor, varun moves downstream at speed =24 +12=36km/hr and upstream at speed = 24-12= ... Upstream Speed])] = (36*12)/0.5(36+12) km/hr = 432/24 km/hr = 18 km/hr

asked
Jan 9
by
anonymous

A lamp of 100W at 200V is supplied current at 100 volts. It will be equivalent to the lamp of: a. 50W b. 40W c. 25W d. 10W

A lamp of 100W at 200V is supplied current at 100 volts. It will be equivalent to the lamp of: 25W

asked
May 17, 2018
by
anonymous

If the supply frequency of a 3-phase induction motor is ‘f’, then frequency of rotor emf at motor slip ‘s’ will be (a) sf (b) (1 – s)f (c) f/s (d) None of these

asked
Apr 10, 2018
by
anonymous

The synchronous speed of an 8 pole induction motor supplied power from a 50 Hz source will be ?

Ns equals f/pair pole 50/4 - 12.5

asked
Dec 31, 2017
by
anonymous

A 200 V, 50 Hz inductive circuit takes a current of 10 A at 30 degree lagging pf, what is the inductive reactance of the circuit? (A) 17.8 Ω (B) 100 Ω (C) 178 Ω (D) 10 Ω

asked
Apr 5, 2018
by
anonymous

If a wire of resistance R is melted and recast to half of its length, then the new resistance of the wire will be

R/4

asked
Jan 21
by
anonymous

asked
Apr 26, 2019
by
Hussein

The number of poles in a phase induction motor at 50 Hz and running at 1500 rpm will be?

The number of poles in a phase induction motor at 50 Hz and running at 1500 rpm will be 4.

asked
Mar 26, 2018
by
anonymous

For a frequency of 200 Hz, the time period will be?

For a frequency of 200 Hz, the time period will be 0.005 s.

asked
Mar 24, 2018
by
anonymous

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