### Basic Electrical Science (Practice Test)

1) Two equal resistors R connected in series across a voltage source V dissipate power P. What would be the power dissipated in the same resistors when they are connected in parallel across the same voltage source ?

A. 4P

B. P

C. 2P

D. 16P

2) Two identical resistors are first connected in parallel then in series. The ratio of resultant resistance of the first combination to the second will be

A. 4

B. 0.25

C. 2

D. 0.5

3) The ratio of the resistance of a 200W, 230V lamp to that of a 100W, 115V lamp will be

A. 0.5

B. 2

C. 4

D. 0.25

4) The resistance of 200W 200V lamp is

A. 100 Ω

B. 200 Ω

C. 400 Ω

D. 800 Ω

5) Two 1 kΩ 1 W resistors are connected in series. Their combine resistance and wattage will be

A. 2 kΩ, 0.5 W

B. 1 kΩ, 1 W

C. 0.5 kΩ, 2 W

D. 2 kΩ, 1 W

6) Three 3 Ω resistors are connected to form a triangle. What is the resistance between any two of the corners ?

A. 9 Ω

B. 6 Ω

C. 3 Ω

D. 2 Ω.

7) A wire of 0.14 mm diameter and specific resistance 9.6 μΩ - cm is 440 cm long. The resistance of the wire will be

A. 9.6 Ω

B. 11.3 Ω

C. 13.7 Ω

D. 27.4 Ω

8) A 10 Ω resistor is stretched to increase its length double. Its resistance will now be

A. 40 Ω

B. 20 Ω

C. 10 Ω

D. 5 Ω

9) Specific resistance is measured in

A. mho

B. ohm

C. ohm - cm

D. ohm/cm

10) A wire of resistance R has it length and cross - section both doubled. Its resistance will become

A. 0.5R

B. R.

C. 2R

D. 4R

11) 5 10

A. 0.1 mA.

B. 1 mA

C. 10 mA

D. 100 mA

12) Three element having conductance G1, G2 and G3 are connected in parallel. their combined conductance will be

A. (G1 + G2 + G3)

B. G1 + G2 + G3

C. 1/G1 + 1/G2 + 1/G3

D. (1/G1 + 1/G2 + 1/G3)

13) Which of the following has negative temperature coefficient ?

A. Electrolytes.

B. Brass.

C. Copper.

D. Silver.

14) Which of the following has positive temperature coefficient ?

A. Germanium.

B. Gold

C. Paper

D. Rubber

15) A 60 W bulb in series with a room heater is connected across the mains. If the 60 W bulb is replaced by 100 W bulb

A. the heater output will increase

B. the heater output will decrease

C. the heater output will be same

D. the heater output will slightly decrease.

16) A cube of material of side 1 cm has a resistance of 0.002 Ω between its opposite faces. If the same volume of the material has a length of 4 cm and a uniform cross - section, the resistance of this length will be

A. 0.128 Ω

B. 0.064 Ω

C. 0.032 Ω

D. 0.016 Ω

A. 4P

B. P

C. 2P

D. 16P

2) Two identical resistors are first connected in parallel then in series. The ratio of resultant resistance of the first combination to the second will be

A. 4

B. 0.25

C. 2

D. 0.5

3) The ratio of the resistance of a 200W, 230V lamp to that of a 100W, 115V lamp will be

A. 0.5

B. 2

C. 4

D. 0.25

4) The resistance of 200W 200V lamp is

A. 100 Ω

B. 200 Ω

C. 400 Ω

D. 800 Ω

5) Two 1 kΩ 1 W resistors are connected in series. Their combine resistance and wattage will be

A. 2 kΩ, 0.5 W

B. 1 kΩ, 1 W

C. 0.5 kΩ, 2 W

D. 2 kΩ, 1 W

6) Three 3 Ω resistors are connected to form a triangle. What is the resistance between any two of the corners ?

A. 9 Ω

B. 6 Ω

C. 3 Ω

D. 2 Ω.

7) A wire of 0.14 mm diameter and specific resistance 9.6 μΩ - cm is 440 cm long. The resistance of the wire will be

A. 9.6 Ω

B. 11.3 Ω

C. 13.7 Ω

D. 27.4 Ω

8) A 10 Ω resistor is stretched to increase its length double. Its resistance will now be

A. 40 Ω

B. 20 Ω

C. 10 Ω

D. 5 Ω

9) Specific resistance is measured in

A. mho

B. ohm

C. ohm - cm

D. ohm/cm

10) A wire of resistance R has it length and cross - section both doubled. Its resistance will become

A. 0.5R

B. R.

C. 2R

D. 4R

11) 5 10

^{16 }electrons pass across the section of a conductor in 1 minutes and 20 seconds. The current flowing isA. 0.1 mA.

B. 1 mA

C. 10 mA

D. 100 mA

12) Three element having conductance G1, G2 and G3 are connected in parallel. their combined conductance will be

A. (G1 + G2 + G3)

^{-1}^{}

C. 1/G1 + 1/G2 + 1/G3

D. (1/G1 + 1/G2 + 1/G3)

^{-1}13) Which of the following has negative temperature coefficient ?

A. Electrolytes.

B. Brass.

C. Copper.

D. Silver.

14) Which of the following has positive temperature coefficient ?

A. Germanium.

B. Gold

C. Paper

D. Rubber

15) A 60 W bulb in series with a room heater is connected across the mains. If the 60 W bulb is replaced by 100 W bulb

A. the heater output will increase

B. the heater output will decrease

C. the heater output will be same

D. the heater output will slightly decrease.

16) A cube of material of side 1 cm has a resistance of 0.002 Ω between its opposite faces. If the same volume of the material has a length of 4 cm and a uniform cross - section, the resistance of this length will be

A. 0.128 Ω

B. 0.064 Ω

C. 0.032 Ω

D. 0.016 Ω

**Answers**
1. a 2.
b 3. b 4. b 5. a 6. d 7.
d 8. a 9. c 10. b 11. a 12.
b 13. a 14.
b 15. a 16.
c

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