Tag: current electricity and magnetism

Questions Related to current electricity and magnetism

When two batteries are connected in series the voltage in the circuit will _____________ .

physics current electricity and magnetism electric cells and batteries

  1. increase

  2. decrease

  3. remains same

  4. first decrease than increase

Show answer
Correct Option: A
Explanation:

In a series connection the positive terminal of the first battery is connected to the negative terminal of the second battery.

And the Equivalent voltage of the battery is the sum of the voltage of individual cell.So, when two batteries are connected in series the voltage in the circuit will increases.
Therefore, A is correct option.

Choose the wrong option

physics current electricity and magnetism electric cells and batteries

  1. A cell is a single unit which converts chemical energy to electrical energy to deliver a voltage while a battery is composed of a number of cells in series to get increased voltage

  2. A Battery is a single unit which converts chemical energy to electrical energy to deliver a voltage while a cell is composed of a number of batteries in series to get increased voltage

  3. In the combination of cells, cells are connected in such a way that negative terminal of a cell is connected to positive terminal of the next cell

  4. In the combination of cells, cells are connected in such a way that negative terminal of a cell is connected to negative terminal of the next cell

Show answer
Correct Option: B,D
Explanation:

Both cell and battery store the chemical energy and then transforms the stored chemical energy to electrical energy. But cell is a single unit with positive and negative terminal whereas battery is a combination of cells connected end to end i.e. positive  to negative terminal.

While making a battery ___________  of a cell is connected to ________ of other cell.

physics current electricity and magnetism electric cells and batteries

  1. negative terminal , negative terminal

  2. positive terminal , negative terminal

  3. positive terminal , positive terminal

  4. neutral terminal ,negative terminal

Show answer
Correct Option: B
Explanation:

While making a battery, negative end of battery is connected to positive terminal of other cell and so on.


Answer-(B)

An electric bell has a resistance of $5 \Omega$ and requires a current of $0.25\ A$ to work it. Assuming that the resistance of the bell wire is $1 \Omega$ per $15m$ and that the bell push is $90m$ distance from the bell. How many cells each of emf $1.4V$ and internal resistance $2 \Omega$, will be required to work the circuit.

physics electric current and its effects electric bell the magnetic effect of a current current electricity and magnetism

  1. $3$

  2. $4$

  3. $5$

  4. $Can't\ be\ determined$

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Correct Option: C

Name one device that uses an electromagnet.

physics electric current and its effects electric bell the magnetic effect of a current current electricity and magnetism

  1. Electric bell

  2. Barometer

  3. Lactometer

  4. All the above

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Correct Option: A

What material is used for making the armature of an electric bell ? Give a reason for using this material.

physics current electricity and magnetism electric bell the magnetic effect of a current electromagnetic forces oersted experiment oersted's experiment magnetic field due to a straight current carrying conductor

  1. Soft Iron

  2. Carbon

  3. Glass

  4. Silicon

Show answer
Correct Option: A
Explanation:

Soft iron is used for making the armature of an electric bell because soft iron is magnetised easily on passing the current and completely demagnetised easily on withdrawing the current through the solenoid.

Working of electric bells is an example of

physics current electricity and magnetism electric bell the magnetic effect of a current electromagnetic forces oersted experiment oersted's experiment magnetic field due to a straight current carrying conductor

  1. Mechanical effect of electric current

  2. Heating effect of electric current

  3. Magnetic effect of electric current

  4. None of these

Show answer
Correct Option: C
Explanation:

An electric bell contains an electromagnet, consisting of coils of insulated wire wound round iron rods. When an electric current flows through the coils, the rods become magnetic and attract a piece of iron attached to a clapper. The clapper hits the bell and makes it ring.

Electric door bell employs

physics current electricity and magnetism electric bell the magnetic effect of a current electromagnetic forces oersted experiment oersted's experiment magnetic field due to a straight current carrying conductor

  1. Permanent Magnet

  2. Electromagnet

  3. Thermistor

  4. Electric bulb

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Correct Option: B
Explanation:

Striker is moved under influence of electromagnet when circuit is complete.

When the switch of an electric bell is pushed.

physics current electricity and magnetism electric bell the magnetic effect of a current electromagnetic forces oersted experiment oersted's experiment magnetic field due to a straight current carrying conductor

  1. Flow of the current stops through the electromagnet in the bell

  2. Current starts to flow through the electromagnet

  3. Voltage decreases in the current flowing through the electromagnet

  4. None of the above

Show answer
Correct Option: B
Explanation:

When the switch of electric bell is pushed,circuit completes and current flows leading an electromagnet to attract armature and ring the bell.

Which of the following is not a component of electric bell?

physics current electricity and magnetism electric bell the magnetic effect of a current electromagnetic forces oersted experiment oersted's experiment magnetic field due to a straight current carrying conductor

  1. Gong

  2. Ferromagnetic strip

  3. Low magnetic field permanent magnet to attract ferromagnetic strip

  4. None of the above

Show answer
Correct Option: C
Explanation:

Electric bell works on the mechanism of electromagnets i.e, temporary magnets, and no permanent magnet is used.

Temporary magnet allows the ferromagnetic strip to return back to its initial state as switch is released.