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प्रश्न
Define the following:
Electromotive force
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उत्तर
Electromotive force: When no current is drawn from a cell, when the cell is in open circuit, the potential difference between the terminals of the cell is called its electromotive force (or e.m.f.).
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संबंधित प्रश्न
In 10 s, charge of 25 C leaves a battery, and 200 J of energy are delivered to an outside circuit a result.
What is the p.d. across the battery?
A 5 V battery is connected to two 20 Ω resistors which are joined together in series.
(a) Draw a circuit diagram to represent this. Add an arrow to indicate the direction of conventional current flow in the circuit.
(b) What is the effective resistance of the two resistors?
(c) Calculate the current that flows from the battery?
(d) What is the p.d. across each resistor?
Two resistors P and Q of the same material and length but of different thickness are connected in parallel to a battery. The cross- sectional area of P is twice that of Q. What is the ratio of
(a) The resistance of P to the resistance of Q?
(b) The current in P to the current in Q?
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
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 energy dissipated in the bulb in 10 minutes.
Problems for practice:
If 5A current flows through a circuit, then convert the current in terms of microampere?
An ammeter is always placed in parallel with the circuit.
