A. a column of mercury
B. a cube of carbon
C. a cube of copper
D. the unit length of wire
Related Mcqs:
- If a wire conductor of 0.2 ohm resistance is doubled in length, its resistance becomes______________?
A. 0.4 ohm
B. 0.6 ohm
C. 0.8 ohm
D. 1.0 ohm - Three 6 ohm resistors are connected to form a triangle. What is the resistance between any two corners ___________?
A. 3/2 Q
B. 6 Q
C. 4 Q
D. 8/3 Q - The resistance of a parallel circuit consisting of two branches is 12 ohms. If the resistance of one branch is 18 ohms, what is the resistance of the other ?
A. 18 Q
B. 36 Q
C. 48 Q
D. 64 Q - Ohm’s law is not applicable to____________?
A. vacuum tubes
B. carbon resistors
C. high voltage circuits
D. circuits with low current densities - Ohm’s law is not applicable to__________?
A. semi-conductors
B. D. C. circuits
C. small resistors
D. high currents - The condition for the validity under Ohm’s law is that_______________?
A. resistance must be uniform
B. current should be proportional to the size of the resistance
C. resistance must be wire wound type
D. temperature at positive end should be more than the temperature at negative end - An open resistor, when checked with an ohm-meter reads_____________?
A. zero
B. infinite
C. high but within tolerance
D. low but not zero - The resistance of a conductor of diameter d and length l is R Ω. If the 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 - Copper wire of certain length and resistance is drawn out to three times its length without change in volume, the new resistance of wire becomes__________?
A. 1/9 times
B. 3 times
C. 9 times
D. unchanged - Two copper conductors have equal length. The cross-sectional area of one conductor is four times that of the other. If the conductor having smaller cross-sectional area has a resistance of 40 ohms the resistance of other conductor will be_____________?
A. 160 ohms
B. 80 ohms
C. 20 ohms
D. 10 ohms