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प्रश्न
What is an electric current?
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उत्तर
An electric current is the flow of electric charge called electrons in a conductor and its magnitude is the amount of electric charge passing through a given point of the conductor in one second.
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संबंधित प्रश्न
Choose the correct alternative and rewrite the following sentence.
When the resistance of a conductor increases, the current will ________ increase.
Three 2 V cells are connected in series and used as a battery in a circuit.
How many joules of electrical energy does 1 C gain on passing through (i) one cell (ii) all three cells?
By what name is the physical quantity coulomb/second called?
What actually travels through the wires when you switch on a light?
Which particles constitute the electric current in a metallic conductor?
(a) With the help of a circuit diagram, obtain the relation for the equivalent resistance of two resistances connected in parallel.
(b) In the circuit diagram shown below, find:
(i) Total resistance.
(ii) Current shown by the ammeter A
Which type of circuit, series or parallel, is preferred while connecting a large number of bulbs:
(b) for lighting inside the rooms of the hotel?
In the circuit shown in fig. 6, find the reading of the ammeter A when the switch S is
(a) Opened.
(b) Closed.
A 3 pin mains plug is fitted to the lead for a 1 kW electric kettle to be used on a 250 V A.C. supply. Which of the following statements is NOT correct?
(a) A 13 A fuse is the most appropriate value to use.
(b) The brown wire should be connected to the live side of the mains.
Fig . shows the core of a transformer and i ts input and output connections
State the material used for the core and describe th e structure of the core.
(a) Use the values given in the diagram to calculate the turns ratio for the transformer and connections, labeling all parts of the diagram .
(b) If a current of 2 A is taken from th e output, calculate th e current in the input circuit (Assume the transformer to be ideal ).
Electrical power P is given by the expression P = (Q × V) ÷ time
(a) What do the symbols Q and V represent?
(b) Express the power P in terms of current and resistance explaining the meanings of symbols used there in.
An electric iron is rated 750 W, 230 V. Calculate the electrical energy consumed by the press in 16 hours.
A geyser is rated 1500 W, 250 V. This geyser is connected to 250 V mains. Calculate:
- The current drawn,
- The energy consumed in 50 hours, and
- The cost of energy consumed at ₹ 4.20 per kWh.
State expression for Cells connected in series.
Match the items in column-I to the items in column-II:
| Column - I | Column - II | ||
| (i) | electric current | (a) | volt |
| (ii) | potential difference | (b) | ohm meter |
| (iii) | specific resistance | (c) | watt |
| (iv) | electrical power | (d) | joule |
| (v) | electrical energy | (e) | ampere |
Problems for practice:
If 5A current flows through a circuit, then convert the current in terms of microampere?
