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प्रश्न
If the current passing through a conductor is doubled, what will be the change in heat produced
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उत्तर
If the current passing through a conductor is doubled, the heat produced will increase by four times because the heat produced is directly proportional to the square of the current
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संबंधित प्रश्न
1 A = _________ mA
- 102
- 103
- 10-3
- 10-6
Calculate the number of electrons constituting one coulomb of charge.
Fill in the blank:
To increase the effective resistance in a circuit the resistors are connected in _____________.
Draw the electrical symbols of the following components and state its use:
Rheostat (variable resistance)
The figure given below shows an electric circuit in which current flows from a 6 V battery through two resistors.
- Are the resistors connected in series with each other or in parallel?
- For each resistors, state the p.d. across it.
- The current flowing from the battery is shared between the two resistors. Which resistor will have bigger share of the current?
- Calculate the effective resistance of the two resistors.
- Calculate the current that flows from the battery.
Define the term resistivity.
The diagram shows two ways of connecting three lamps P, Q and R to A.C. supply of 220 V.
Tick(✓) the correct choice in the following:
Which of the following quantities has the same value for all electrical
appliances connected to the ring main circuit in a house?
Define the following:
Super conductors
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.
If a fuse contains a 5 A fuse wire and the voltage is 240 V, what is the maximum power (wattage) which may be taken from the circuit?
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.
If the potential differences between two parts of a thundercloud is 10s V,
what is the amount of energy given up during the passage of 20 coulombs?
(a)2x10-7J
(b)200J
(c)Sx106 j
(d)2x 109J
(e)2x 1010 J
Three resistances, of which two are equal when connected in series have an effective resistance of 30 ohms. When the three resistances are connected in parallel, the effective resistances is 3 ohms. Find the values of the individual resistances.
Problems for practice:
If 3A current flows through a circuit, then convert the current in terms of a milliampere.
Define the following:
Conventional current
