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2-T uniform magnetic field makes an angle of 30° with the z axis. The magnetic flux through a 3-m^2 portion of the xy plane is

• 2.0 Wb

• 3.0 Wb

• 5.2 Wb

• 6.0 Wb

An RLC series circuit has L=100 mH and C=1μF. It is connected to a 1000-Hz source and the source emf is found to lead the current by 75°. The value of R is

• 12.6 ohms

• 126 ohms

• 175 ohms

• 1750 ohms

An RL series circuit is connected to an ac generator with a maximum emf of 20V. If the maximum potential difference across the resistor is 16V, then the maximum potential difference across the inductor is

• 2 V

• 4 V

• 12 V

• 25.6 V

A 35-μF capacitor is connected to a source of sinusoidal emf with a frequency of 400 Hz and a maximum emf of 20 V. The maximum current is

• 0.28 A

• 1.8 A

• 230 A

• 1400 A

One primary and one secondary terminal of a twowinding transformer are connected to an ohm-meter instrument. What will be the reading on this instrument?

• Infinity

• Equal to winding resistance

• Zero to infinity

• zero

An ideal single phase transformer has a voltage rating of 2300/230 V. A motor to be connected across the secondary will draw 30 A at 200 V. What value of resistance in ohms to be connected in the primary circuit to have 200 V across the motor during operation?

• 50

• 60

• 80

• 100

A transformer has primary and secondary turns of 60 and 240, respectively. If 60 turns winding has 5% tap, calculate the primary voltage applied in volts to 95% of the winding that will permit the rated output voltage of 480 V

• 204

• 112

• 114

• 118

A single phase transformer is rated 1 kVA, 240/120 V, 60Hz. Because of an emergency, the transformer has to be used on a 50Hz system. If the flux density in the transformer core is to be kept the same as at 60Hz and 240 V, what voltage should be applied at 50Hz in volts?

• 180

• 300

• 240

• 200

A parallel-pate capacitor has a plate are of 0.3 m^2 and a plate separation of 0.1 mm. If the charge on each plate has a magnitude of 5 x 10^-6 C then the force exerted by one plate on the other has a magnitude of about

• 0

• 5 N

• 9 N

• 1 x 10^4 N

A parallel-plate capacitor has a plate area of 0.2 m^2 and a plate separation of 0.1 mm. If the charge on each plate has a magnitude of 4 x 10^-6 C the potential difference across the plates is approximately.

• 0

• 4 x 10^-2 V

• 1 x 10^2 V

• 2 x 10^2 V