A. arcs across separating contacts
B. mechanical noise of high intensity
C. both mechanical noise and arc between contacts
D. none of the above
Related Mcqs:
- In a lamp load when more than one lamp are switched on the total resistance of the load_____________?
A. increases
B. decreases
C. remains same
D. none of the above - For testing appliances, the wattage of test lamp should be_____________?
A. very low
B. low
C. high
D. any value - You have to replace 1500 Q resistor in radio. You have no 1500 Q resistor but have several 1000 Q ones which you would connect__________?
A. two in parallel
B. two in parallel and one in series
C. three in parallel
D. three in series - Four wires of same material, the same cross-sectional area and the same length when connected in parallel give a resistance of 25 Q. If the same four wires are connected is series the effective resistance will be________?
A. 100 Ω
B. 200 Ω
C. 300 Ω
D. 400 Ω - Which one of the following does not have negative temperature co-efficient ____________?
A. Aluminium
B. Paper
C. Rubber
D. Mica - The rating of a fuse wire is always expressed in________________?
A. ampere-hours
B. ampere-volts
C. kWh
D. amperes - The hot resistance of the bulb’s filament is higher than its cold resistance because the temperature co-efficient of the filament is___________________?
A. zero
B. negative
C. positive
D. about 2 ohms per degree - When electric current passes through a bucket full of water, lot of bubbling is observeD. This suggests that the type of supply is____________?
A. A. C.
B. D. C.
C. any of above two
D. none of the above - A nichrome wire used as a heater coil has the resistance of 2 £2/m. For a heater of 1 kW at 200 V, the length of wire required will be_____________?
A. 80 m
B. 60 m
C. 40 m
D. 20 m - A thermistor has_____________?
A. positive temperature coefficient
B. negative temperature coefficient
C. zero temperature coefficient
D. variable temperature coefficient
