D.C Basic and network and electromagnetic theory. Part – 5

41. The ratio of voltage and current in a closed circuit

A. Remains constant

B. Varies

C. Increases

D. Falls

42. The resistance of wire varies inversely as

A. Area of cross section

B. Length

C. Resistivity

D. Temperature

43. The material having a few number of free electrons and offering very high resistance to the flow of electric current are known as

A. Conductors

B. Insulators

C. Semiconductors

D. None of the these

44. Dielectric strength of a material depends on

A. Temperature

B. Thickness

C. Moisture content

D. All of these

45. If a copper conductor is moved across a magnetic field

A. The wire will become magnetic

B. A voltage will be induced in the wire

C. A current will be induced in the wire

D. Nothing will happen

46.  An instantaneous change in voltage is not possible in

A. A resistor

B. An inductor

C. A capacitor

D. A current source

47. Resistivity of a wire depends on

A. Length

B. Material

C. Cross section area

D. None of the above

48. If 1A current flows in a circuit, the number of electrons flowing through this circuit is

A. 1.6 × 10¹⁹

B. 0.624 × 10¹⁸

C. 1.6 × 10^-19

D. 0.625 ×10^-19

49. The resistance of a conductor of diameter D and length L is RΩ. if diameter of the conductor is halved and its length is doubled, the resistance will be

A. R Ω

B. 2R Ω

C. 4R Ω

D. 8R Ω

50. How many coulombs of charge flow through a circuit carrying a current of 10A In 1 minute?

A. 10

B. 60

C. 600

D. 1200