Three identical bulbs, B1, B2 and B3 connected. Current of 3A is recorded by the ammeter when the bulbs glow.

Three identical bulbs, B1, B2 and B3 connected. A current of 3A is recorded by the ammeter when ​the bulbs glow. What happens when:

To the glow of the other two bulbs when one of them gets fused?

Assuming that B1 is fused, there supposedly will be no impact on the other two bulbs. The two bulbs will remain the same since they are dependent on the power. This happens because the potential difference and resistance of the other two bulbs remain the same, and do not get affected by an external fuse of another bulb.

To the reading of A1, A2, A3 and A when the bulb B2 gets fused? 

Considering that there are parallel connections, the net resistance should be:

1/R = 1/R1 + 1/R2 + 1/R3

Now, since the resistance remains same, thus, R’ = R/3

Hence, according to Ohm’s Law,

V = IR

Thus,

R = 4.5Ω

Assuming that B2 is fused, two bulbs, B1 and B3, remain parallel

Therefore, the net resistance in parallel combination is = 1/R’ = 2/R

⇒ R’ = 4.5/2 Ω

⇒ I = V/R’

⇒ I = 2 × 4.5 / 4.5

⇒ I = 2A

The distribution of current in both the bulbs will be1 A each.

How much power is dissipated in the circuit when all the three bulbs glow together?

The amount of power that is dissipated when all the three bulbs glow together:

P = V × I

Therefore, after replacing the values, we get,

P= 4.5 × 3

⇒ P = 13.5 W


Related Questions:

  1. How Do You Find The Resistance Of A Wire?
  2. Why is the curve representing Ohm's law linear?
  3. State Ohms law. How can it be verified experimentally?
  4. What Is The Formula Of Ammeter?
  5. What are the limitations of Ohm's Law?
  6. What is the necessary condition for a conductor to obey Ohm's Law?
  7. How many 176 Ω resistors (in parallel) are required to carry 5 A on a 220 V line?
  8. n identical light bulbs, each designed to draw P power from a certain voltage supply, are joined in series across that supply. The total power which they will draw is?
  9. Two bulbs are rated (P1, V) and (P2, V). If they are connected (i) in series and (ii) in parallel across a supply V Find the power dissipated in the two combinations in terms of P1 and P2.
  10. Does Current Increase With Voltage?
  11. The resistance R= V/I, where V=100 ± 5.0V and I = 10 ± 0.2A. What is the total error in R?
  12. State Ohms Law. Express It Mathematically. Define Si Unit Of Resistance.
  13. Is resistance constant in Ohm's law?
  14. Draw a circuit diagram to verify ohm’s law.
  15. How do you find the resistance in Ohm's law?
  16. What are the applications of ohm's law used in daily life?

Check Out:

CBSE CLASS XII Related Questions

  • 1.
    Capacitors are manufactured with certain standard capacitances and working voltages. However, these standard values may not be the ones that are actually needed in a particular application. Two or more capacitors can be grouped in series or in parallel to achieve desired capacitance and voltage. When connected in series, the total capacitance decreases while the voltage rating increases, whereas in parallel connections, the total capacitance increases and maintains the same voltage rating. A capacitor stores energy in the electric field between its plates and stored energy is proportional to the square of the voltage and capacitance $U = \frac{1}{2}CV^2$, where symbols have their usual meanings.
    Two capacitors, one of $3 \ \mu$F and the other of $6 \ \mu$F, are connected in series in the circuit as shown in the figure, for a long time. }


      • 2.
        Read the following paragraph and answer the questions that follow.
        In an experiment with convex lens of focal length f, the screen is fixed at a distance D from the object. A student slowly moves the lens away from the object towards the screen and finds that she is able to form sharp image of the object for two positions of the lens. The distance between these two positions of the lens is d.


          • 3.
            A student sets up the circuit as shown in the figure to find the value of unknown resistance X and records a set of readings of the voltmeter and the ammeter by using the rheostat.


              • 4.
                An astronomical telescope consists of two converging lenses. One of them of large aperture and large focal length is called objective lens and the other one, of smaller focal length and smaller aperture is called the eyepiece. It is used to see distant objects which are not seen clearly with naked eyes. The image formed by the objective lens acts as an object for the eyepiece and the final image produced by the eyepiece is magnified.


                  • 5.
                    Consider a cylindrical conductor of length \( l \) and area of cross-section \( A \). Current \( I \) is maintained in the conductor and electrons drift with velocity \( \vec{v}_d \, (|\vec{v}_d| = \frac{eE}{m} \tau) \), where symbols have their usual meanings. Show that the conductivity of the material of the conductor is given by \[ \sigma = \frac{n e^2 \tau}{m}. \]


                      • 6.
                        An electric field $\vec{E}$ is established across the ends of a cylindrical conductor of length L and area of cross-section A. Discuss how electrons attain an average velocity, independent of time. Hence, obtain a relation between current in the conductor and this ‘average velocity’ of electrons.

                          CBSE CLASS XII Previous Year Papers

                          Comments


                          No Comments To Show