Advertisements
Advertisements
Question
In an electrical circuit three incandescent bulbs A, B and C of rating 40 W, 60 W and 100 W respectively are connected in parallel to an electric source. Which of the following is likely to happen regarding their brightness?
Options
Brightness of all the bulbs will be the same
Brightness of bulb A will be the maximum
Brightness of bulb B will be more than that of A
Brightness of bulb C will be less than that of B
Advertisements
Solution
Brightness of bulb B will be more than that of A
Explanation -
Since all the three bulbs are connected in parallel so potential difference (V) across all the bulbs is same. Power dissipated is given by
`"P" = "V"^2/"R"`
Lower the resistance, higher the power dissipation. Hence higher the brightness.
Out of all the three bulbs, 100 W bulb will have minimum resistance because rated voltage of all the bulbs will be same and its power dissipation is maximum.
Thus, 100 W will have maximum brightness and 40 W bulb will have minimum brightness.
RELATED QUESTIONS
Draw the labelled diagram of an electric circuit comprising of a cell, a resistance, an ammeter, a voltmeter and a closed switch (or closed plug key). Which of the two has a large resistance : an ammeter or a voltmeter?
How does the short circuit form?
The following figure shows the symbols for components used in the accompanying electrical circuit. Place them at proper places and complete the circuit.
Which law can you prove with the help of above circuit?
Resistances R1, R2, R3 and R4 are connected as shown in the figure. S1 and S2 are two keys. Discuss the current flowing in the circuit in the following cases.
- Both S1 and S2 are closed.
- Both S1 and S2 are open.
- S1 is closed but S2 is open.
A battery is to be formed by joining 3 dry cells with connecting wires. Show how will you connect the wires by drawing a diagram.
Draw a neat diagram showing a open electric circuit.
In any electric circuit, when the switch is on and the current flows through it why do the wire, switches, bulb or devices become hot?
Nowadays MCBs are used in homes, for stop the current in the circuit which suddenly increases.
______ is the device used to close or open an electric circuit.
Study the electric circuit below. Which of the following switches should be closed so that only two bulbs will light up
Study the three electric circuits below. Each of them has a glass rod (G), a steel rod (S), and a wooden rod (W).
In which of the electric circuits would the bulb not light up.
_____ has a thin metallic filament that melts and breaks the connection when the circuit is overheated.
What is electric circuit?
What is the role of the earth wire in domestic circuits?
In a circuit, if the key is in open (off) condition, then electricity will not flow.
Choose the statement which is not correct in the case of an electric fuse.
Observe the circuit given:
1. Would any of the bulbs glow when the switch is in the ‘OFF’ position?
2. What will be the order in which the bulbs A, B, and C will glow when the switch is moved to the ‘ON’ position?
In the above circuit, if the current reading in the ammeter A is 2A, what would be the value of R1?
Will the bulb glow in the circuit shown in the following figure? Explain.
How is Joule's law effect useful in electric circuits where fuse is used as a safety device?
