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प्रश्न
What is an Ammeter? How is It Connected in a Circuit? Draw a Diagram to Illustrate Your Answer.
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उत्तर
An ammeter is an instrument that is used to measure electric current. It is always connected in series with the circuit in which the current is to be measured.
Suppose we want to find out the current flowing through a conductor AB. Here, we should connect the ammeter in series with the conductor AB as above.
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संबंधित प्रश्न
Which of the following units could be used to measure electric charge?
(a) ampere
(b) joule
(c) volt
(d) coulomb
Three 2 V cells are connected in series and used as a battery in a circuit.
What is the p.d. at the terminals of the battery?
A flash of lighting carries 10 C of charge which flows for 0.01 s. What is the current? If the voltage is 10 MV, what is the energy?
If the current through a floodlamp is 5 A, what charge passed in 10 seconds?
(a) 0.5 C
(b) 2 C
(c) 5 C
(d) 50 C
An electric circuit consisting of a 0.5 m long nichrome wire XY, an ammeter, a voltmeter, four cells of 1.5 V each and a plug key was set up.
Following graph was plotted between V and I values:
What would be the values of `V/I` rations when the potential difference is 0.8 V, 1.2 V and 1.6 V respectively?
What conclusion do you draw from these values?
What is the resistance of the wire?
An electric bulb of resistance 20 Ω and a resistance wire of 4 Ω are connected in series with a 6 V battery.
Draw the circuit diagram, and calculate:
(a) total resistance of the circuit.
(b) current through the circuit.
(c) potential difference across the electric bulb.
(d) potential difference across the resistance wire.
V1, V2 and V3 are the p.ds. across the 1Ω, 2Ω and 3Ω resistors in the following diagram, and the current is 5 A.
Which one of the columns (a) to (d) shows the correct values of V1, V2 and V3measured in volts?
`V_1` `V_2` `V_3`
(a) 1.0 2.0 3.0
(b) 5.0 10.0 15.0
(c) 5.0 2.5 1.6
(d) 4.0 4.0 2.0
Draw a circuit diagram to show how two 4 V electric lamps can be lit brightly from two 2 V cells.
The rating of a fuse connected in the lighting circuit is:
(a) 15 A (b) 5 A (c) 10 A (d) Zero
If a charge of 420 C flows through a conducting wire in 5 minutes what is the value of the current?
Complete the following table. The first answer has been given as an example
| Quantity | Unit |
|
(a) Electrical potential Volt ( b) Resistance ( c) Power ( d) Energy ( e) Resistivity |
Volt ........ .......... ............ .............. |
An electric kettle has a heating element which is rated at 2 kW when connected to a 250 V electric supply. Calculate the
(a) Current which flows in the element when it is connected to a 250 V supply,
(b) Resistance of the filament,
(c) Heat produced in 1 minute by the element,
(d) Cost of running the kettle for 10 minutes a day for 30 days of the month, at the rate of Rs. 3.00 per unit.
An auto lamp is joined to a battery of e.m.f. 4 V and internal resistance 2.5Ω. A steady current of 0.5 A flows through the circuit. Calculate the
(a) Total energy provided by battery in 10 minutes,
(b) Heat dissipated in the bulb in 10 minutes.
Complete the following:
1 kWh = _________ J
An electric bulb is marked '100 W, 250 V'. What information does this convey?
At the time of short circuit, the electric current in the circuit ______.
Conventionally, the direction of the current is taken as:
Problems for practice:
If 5A current flows through a circuit, then convert the current in terms of microampere?
