D.C Basic and network and electromagnetic theory. Part – 1

1. Two wires A and B of the same material and length L and 2L have radius (R) and (2R) respectively. The ratio of their specific resistance will be

A. 1:1

B. 2:1

C. 1:1

D. 1:8

2. The color code on a carbon resistor is (yellow, brown, red). The value of resistance is

A. 4100 Ω

B. 4100 Ω ± 20%

C. 4100 Ω ± 20% ohm

D. 41 ohm

3. Two electric lamps each of 40W 230V are connected in series across 230V supply. The power consumed by each lamp will be approximately.

A. 10W

B. 20W

C. 40W

D. 80W

4. The rating of an electric bulb is 220V,100W. It is operated at 110V, the power consumed by it will be

A. 50W

B. 75W

C. 90W

D. 25W

5. Which of the following relation is incorrect?

A. P=VI

B. I=

C. P=V/R²

D. V=

6. An air gap is usually inserted in magnetic circuits to

A. Increase the flux

B. Prevent saturation

C. Increase m.m.f.

D. Decrease flux

7. The energy stored in an electric field is given by the expression

A. CV²

B. CV

C. C²V

D.

8. While testing a capacitor with ohmmeter, if the capacitor shows charging but the final resistance reading is appreciably less than the normal capacitor is-

A. Leaky

B. Open – circuited 

C. Short – circuited

D. Satisfactory

9. Which of the following is not expressed in ohms?

A. Inductance

B. Capacitance

C. Inductive reactance

D. Both A and B

10. In a parallel connection of resistors equivalent resistance is

A. More than the largest resistor

B. Smaller than the smallest resistor

C. In between smaller and larger resistor

D. None of the above