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प्रश्न
Draw a circuit diagram to show how two 4 V electric lamps can be lit brightly from two 2 V cells.
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उत्तर
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संबंधित प्रश्न
Define the unit of current.
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?
A car headlight bulb working on a 12 V car battery draws a current of 0.5 A. The resistance of the light bulb is:
(a) 0.5 Ω
(b) 6 Ω
(c) 12 Ω
(d) 24 Ω
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?
Calculate the effective resistance between the points A and B in the network shown below in Figure 8.45
Tell the odd one out. Give a proper explanation.
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?
Two cells each having an e.m.f. of 2 V and an internal resistance of 2Ω are
connected (a) In series, and ( b) In para 1le l as shown in fig. . What is the
current flowing through the cir cu it in each_ case?
60 joules of heat was dissipated in a resistor when 20 C flowed for 5 s. Calculate:
(a) P.d. across the resistor,
(b) Resistance of the resistor, and
(c) Average power dissipated in the resistor.
State whether the current is a scalar or vector?
Three heaters each rated 250 W, 100 V are connected in parallel to a 100 V supply. The resistance of each heater
State the condition when it is advantageous to connect cells in parallel.
What determines the direction of flow of electrons between two charged conductors kept in contact?
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.
Small amounts of electrical current are measured in milliampere (mA). How many milliampere are there in 0.25 A ?
Define an electric current.
For current to flow, one needs art open circuit.
