Advertisements
Advertisements
प्रश्न
Calculate the current through a 60 W lamp rated 250 V. If the line voltage falls to 200 V, how is power consumed by the bulb affected?
Advertisements
उत्तर
Given ,
Power P = 60 W
Voltage , V = 250 V
As Power , P = VI
I = `60/250 = 0.24 "A"`
Resistance of bulb R = `"V"^2/"P" = 250^2/60 = 1041.6 Omega`
Now if voltage falls to 200 V , power consumed will be
P = `"V"^2/"R" = 200^2/1041.6 = 38.4 "W"`
संबंधित प्रश्न
What is the current in a circuit if the charge passing each point is 20 C in 40 s?
Fill in the folloing blank with suitable words:
A current is a flow of ............... .For this to happen there must be a ............... circuit.
Fill in the folloing blank with suitable words:
Current is measured in ............... using an ............... placed in ............... in a circuit.
In 10 s, charge of 25 C leaves a battery, and 200 J of energy are delivered to an outside circuit a result.
What current flows from the battery?
Which statement/statement is/are correct?
1. An ammeter is connected in series in a circuit and a voltmeter is connected in parallel.
2. An ammeter has a high resistance.
3. A voltmeter has a low resistance.
(a) 1, 2, 3
(b) 1, 2
(c) 2, 3
(d) 1
Tick(✓) the correct choice in the following:
24 watt, 12 volt head lamp is fully lit by connecting it to a 12 volt
battery. The working resistance of the lamp is
A current of 0.3 A is flowing through a branch of 6 Ω resistors in a junction as shown in fig. . Calculate the
(a) P.d. across the junction XY,
(b) Current flowing through 9Ω and 24Ω
( c) P.d. across 24 Ω resistor, and
( d) e.m.f. of the cell.
A bulb is connected to a battery of p.d. 4 V and internal resistance 2.5 Ω . A steady current of 0.5 A flows through the circuit. Calculate:
The resistance of the bulb
Name any two devices, which are working on the heating effect of the electric current.
