SSC JE – Electrical Questions

1.The crest factor of alternating current is…..?

Peak value / RMS value

2. A 0 to 200 V volt meter has a guaranteed accuracy of 1% of full scale reading. The voltage measured by the instrument is 50V. What is the limiting error?

4%

3. Which one of the following materials is used in the fabrication of swamping resistance of a PMMC instrument?

Manganin

4. A 12 bit A/D converter has a range 0-10V what is the approximate resolution of the converter?

2.5 mV

5. In a series RLC circuit, at the resonant frequency…..?

Current is maximum

6. Electrical conductivity is measured in…?

mho/m

7. In induction motor, air gap power is 10 KW and mechanically developed power is 8 KW. What is the rotor ohmic loss?

2 KW

8. A 500 KVA transformer has constant losses of 600 W and copper loss at full load are 2000 W. Then at what load, is the efficiency maximum?

600 W

9. What is the frequency of Rotor current of a 50 Hz induction motor operating at 2% slip?

1 Hz

10. What are slot wedges in a DC machine made of….?

Silicon steel

11. Electric field inside a hallow metallic charged sphere is…?

Zero

12. The magnetic susceptibility of a paramagnetic material is…?

Less than one but positive

13. For vacuum susceptibility is…..?

Zero

14. The Biot- savart’s law is a general modification of…?

Ampere’s law

15. The technique of adding a precise amount time between the trigger point and beginning of the scope sweep in a CRO is known as….?

Delayed sweep