274. A current impulse, 58(t), is forced through a capacitor C. The voltage Ve(t), across the capacitor is given by

A. 5t

B. 5u(t)

C.5u(t)

D.10

275. A de potentiometer is designed to measure up to about 2 V with a slide wire of 800 mm. A standard cell of emf 1.18 V obtains balance at 600 mm. A test cell is seen to obtain balance at 680 mm. The emf of the test cell is

A. 1.00 V

B. 1.34 V

C. 1.50 V

D. 1.70 V

276. A galvanometer with a full scale scurrent of 10 mA has a resistance of 10000 Q. The multiplying power (the ratio of measured current to galvanometer current) of a 100 Q shunt with this galvanometer is

A.110

B.100

C.11

D.10

277. A DC ammeter has a resistance of 0.1Q and its current range is 0-100A. If the range is to be extended to 0-500A, the meter requires the following shunt resistance

A.0.010 E2

B. 0.011 E2

C. 0.025 E2

D. 1.0 E2

278. Two wattmeters, which are connected to measure the total power on a three phase system supplying a balanced load, read 10.5 kW and ?2.5 kW, respectively. The total powere and the power factor, respectively, are

A. 13.0 kW, 0.334

B. 13.0 kW, 0.684

C. 8.0 kW, 0.52

D. 8.0 kW, 0.334

279. The principle of bridge duplex working involves

A. potential balance

B. current balance

C. resistance balance

D. impedance balance

280. The resistances 100 LI ? 5 and * 15 Ll are connected in series. If the errors are specified as standard deviations, theresultant error will be

A.?10

B.

C. ? 15.8

D. ? 20 f2

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