Tag: do liquids conduct electricity?

Questions Related to do liquids conduct electricity?

Pure water is a ________ conductor of electricity.

  1. good

  2. bad

  3. semi

  4. none of the above


Correct Option: B
Explanation:

Pure water does not contain any salts or conducting impurities. Hence, it does not conduct electricity.

Which of the following statements is false?

  1. Vegetables conduct electricity

  2. Passage of electric current will not change the colour of a solution

  3. An electrode conducts electricity

  4. Electroplating is one of the applications of chemical effects of electrical current


Correct Option: B
Explanation:

Passage of electric current may change the colour of a solution.
When an electric current is passed through a solution, a chemical reaction occurs. During this chemical reaction, coloured salts may form or may be consumed. This results in colour change for the solution.

What happens when you join the free ends of the tester for more than a few minutes?

  1. Cells of the battery will drain quickly.

  2. The current will not be able to pass.

  3. There would be no conduction of electricity.

  4. All of the above


Correct Option: A
Explanation:

While checking, your tester does not join its free ends for more than a few seconds. Otherwise, the cells of the battery will drain very quickly.

Which of the following statement is correct while conduction of electricity in lemon juice?

  1. The liquid (lemon juice) allows the electric current to pass through. Hence, the circuit of tester is complete.

  2. The current flows in the circuit of the tester.

  3. The bulb glows which indicates lemon juice is a good conductor of electricity.

  4. All of the above


Correct Option: D
Explanation:

When the liquid (lemon juice) between the two ends of the tester allows the electric current to pass, the circuit of the tester becomes complete. The current flows in the circuit and the bulb glows indicating that lemon juice is a good conductor of electricity.

Which of the following is a poor conductor of electricity?

  1. Air

  2. Tap water

  3. Iron

  4. Silver


Correct Option: A
Explanation:

Air is a poor conductor of electricity.

Which of the following devices can be used to detect a weak current?

  1. Use of electric bulb in tester.

  2. Use of LED in tester.

  3. A tester using magnetic effects of current.

  4. Both B and C


Correct Option: D
Explanation:

LED glows even when a weak electric current flows through it. Also, even if the current is small, the deflection of the magnetic needle can be seen. Hence, tester using LED and magnetic effects of current can be used to detect a weak current.

When the liquid between two ends allow electric current, then :

  1. bulb of tester glows

  2. only heating of the tester takes place

  3. bulb of the tester does not glow

  4. none of the above


Correct Option: A
Explanation:

When the liquid between two ends allow electric current, then the bulb of tester glows. 

When salt is dissolved in distilled water, we obtain salt solution which is a / an :

  1. conductor of electricity

  2. insulator of electricity

  3. motor of electricity

  4. filament of electricity


Correct Option: A
Explanation:

When salt is dissolved in distilled water, we obtain salt solution. This is a conductor of electricity.

Which of the following might be the reason that the current in the circuit is weak?

  1. Circuit of the tester might not be complete.

  2. The material may not be able to conduct electricity as easily as metals.

  3. The circuit of the tester is complete but still the bulb does not glow.

  4. Both A and B


Correct Option: B
Explanation:

Though a material may conduct electricity, it may not conduct it as easily as a metal. As a result, the circuit of the tester may be complete and yet the current through it may be too weak to make the bulb glow.

Which of the following is not true about LED?

  1. There are two wires (called leads) attached to an LED.

  2. While connecting to a circuit, the longer lead of LED is always connected to the positive terminal of the battery.

  3. While connecting to a circuit, the shorter lead of LED is always connected to the positive terminal of the battery.

  4. LED can be used to detect weak current.


Correct Option: C
Explanation:

While connecting to a circuit, the longer lead is always connected to the positive terminal of the battery and the shorter lead is connected to the negative terminal of the battery.