Two bulbs rated (P1, V) and (P2, V) are connected (i) in series and (ii) in parallel across supply V. Determine power in the two combinations P1 and P2.

Electric power can be defined as the rate at which work is done or energy is converted into an electric circuit. In other words, it is the measurement energy used in a span of time.

Step 1:Formula

Electric Power formula is given by:

P = VI

Here (in the circuit),

P = Power
V = Potential Difference
I = Electric Current

Power is often also denoted as,

⇒ P = I²R
⇒ \(P = {{V^2} \over R}\)
\(\therefore\) Expressions above are determined using Ohm’s Law, wherein, Voltage, current, and resistance are interrelated by the relation:

V = IR

Here (in the circuit),

R = Resistance
V = Potential Difference
I = Electric Current

Step 2: Solution

(i) Two bulbs of (P1, V) and (P2, V) that are connected in series:

The flow of current in both bulbs is the same. Assuming R1 and R2 are both resistances of the bulbs, then the effective resistance circuit:

⇒ R = R1 + R2

Now, after using the relation, we can obtain:

P=V²/R

And, R = V²/P

Therefore, V²/P = V1²/ P1 + V2²/P2

As is given, V₁ = V₂ = V.

Therefore,

⇒ 1/P = 1/P₁ + 1/P₂

Hence, effective power of two bulbs connected in series is 1/ P = 1 / P₁ + 1 / P₂

(ii) Two bulbs of (P1, V) and (P2, V) when connected in parallel:

⇒ 1/R = 1/R₁ + 1/R₂

We know that

P = V²/R

1/R = V²/P

As is given, V1 = V2

Thus, P/V2 = P1/V² + P2/V²

Hence, the effective power of two bulbs connected in parallel is P = P₁ + P₂.

More Related Questions:

Also Check:

Important Topics Related to Ohm’s Law
Potentiometer	Electromotive Force	Wheatstone Bridge
Ampere	Cells, emf, Internal Resistance	Derivation of Drift Velocity
Relation between kva and kw	Difference between RTD and thermocouple	Unit of Specific Resistance
Static Electricity	Difference between AC and DC	Types of Current
Current Density	Difference between kva and kw	Permittivity And Permeability
Electric Dipole	Resistor Colour Codes	Meter Bridge
Unit of Current	Relation between resistance and length	Electrical Formula
Kirchhoff’s Rules	Difference between Air Conditioning and Refrigeration	Circuit Diagram
Resistivity Temperature Dependence	Cells in Series and in Parallel	Types of Resistors
Current density formula	Difference Between Primary Cell and Secondary Cell	Internal resistance formula
Resistivity formula	Differences Between Acceleration and Velocity	Power Of Alternating Current
Current Electricity NCERT Solutions	Carbon Resistor	Combination of Resistors
Drift Velocity	Uses of Resistor	Voltage Divider Formula
Difference between Earth and Neutral	Difference between emf and Voltage	Current Electricity
Power transformers	Relation between Power and Resistance	Resistance Formula

CBSE CLASS XII Related Questions

1.
Two parallel plate capacitors X and Y are connected in series to a 6 V battery. They have the same plate area and same plate separation but capacitor X has air between its plates, whereas capacitor Y contains a material of dielectric constant 4. Calculate the capacitances of X and Y, if the equivalent capacitance of the combination of X and Y is \( 4 \, \mu\text{F} \). Calculate the potential difference across the plates of X and Y.

View Solution

2.
Draw the number of scattered particles versus the scattering angle graph for scattering of alpha particles by a thin foil. Write two important conclusions that can be drawn from this plot.

View Solution

3.
If Bohr’s quantization postulate (angular momentum \( = \frac{nh}{2\pi} \)) is a basic law of nature, it should be equally valid for the case of planetary motion also. Why, then, do we never speak of quantization of orbits of planets around the Sun? Explain.

View Solution

4.
Write any two features of nuclear forces.

View Solution

5.
A square loop of side 0.50 m is placed in a uniform magnetic field of 0.4 T perpendicular to the plane of the loop. The loop is rotated through an angle of 60° in 0.2 s. The value of emf induced in the loop will be:

5 V
3.5 V
2.5 V
Zero V

View Solution

6.
If both the number of protons and the neutrons are conserved in each nuclear reaction, in what way is mass converted into energy (or vice versa) in a nuclear reaction? Explain.

View Solution

Two bulbs rated (P1, V) and (P2, V) are connected (i) in series and (ii) in parallel across supply V. Determine power in the two combinations P1 and P2.

Step 1:Formula

Step 2: Solution

CBSE CLASS XII Related Questions

2.
Draw the number of scattered particles versus the scattering angle graph for scattering of alpha particles by a thin foil. Write two important conclusions that can be drawn from this plot.

3.
If Bohr’s quantization postulate (angular momentum \( = \frac{nh}{2\pi} \)) is a basic law of nature, it should be equally valid for the case of planetary motion also. Why, then, do we never speak of quantization of orbits of planets around the Sun? Explain.

4.
Write any two features of nuclear forces.

5.
A square loop of side 0.50 m is placed in a uniform magnetic field of 0.4 T perpendicular to the plane of the loop. The loop is rotated through an angle of 60° in 0.2 s. The value of emf induced in the loop will be:

6.
If both the number of protons and the neutrons are conserved in each nuclear reaction, in what way is mass converted into energy (or vice versa) in a nuclear reaction? Explain.

Similar Physics Concepts

Comments

SUBSCRIBE TO OUR NEWS LETTER

Two bulbs rated (P1, V) and (P2, V) are connected (i) in series and (ii) in parallel across supply V. Determine power in the two combinations P1 and P2.

Step 1:Formula

Step 2: Solution

CBSE CLASS XII Related Questions

2. Draw the number of scattered particles versus the scattering angle graph for scattering of alpha particles by a thin foil. Write two important conclusions that can be drawn from this plot.

3. If Bohr’s quantization postulate (angular momentum \( = \frac{nh}{2\pi} \)) is a basic law of nature, it should be equally valid for the case of planetary motion also. Why, then, do we never speak of quantization of orbits of planets around the Sun? Explain.

4. Write any two features of nuclear forces.

5.A square loop of side 0.50 m is placed in a uniform magnetic field of 0.4 T perpendicular to the plane of the loop. The loop is rotated through an angle of 60° in 0.2 s. The value of emf induced in the loop will be:

6. If both the number of protons and the neutrons are conserved in each nuclear reaction, in what way is mass converted into energy (or vice versa) in a nuclear reaction? Explain.

Similar Physics Concepts

Comments

SUBSCRIBE TO OUR NEWS LETTER

2.
Draw the number of scattered particles versus the scattering angle graph for scattering of alpha particles by a thin foil. Write two important conclusions that can be drawn from this plot.

3.
If Bohr’s quantization postulate (angular momentum \( = \frac{nh}{2\pi} \)) is a basic law of nature, it should be equally valid for the case of planetary motion also. Why, then, do we never speak of quantization of orbits of planets around the Sun? Explain.

4.
Write any two features of nuclear forces.

5.
A square loop of side 0.50 m is placed in a uniform magnetic field of 0.4 T perpendicular to the plane of the loop. The loop is rotated through an angle of 60° in 0.2 s. The value of emf induced in the loop will be:

6.
If both the number of protons and the neutrons are conserved in each nuclear reaction, in what way is mass converted into energy (or vice versa) in a nuclear reaction? Explain.