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प्रश्न
Two cells of emfs 1.5 V and 2.0 V, having internal resistances 0.2 Ω and 0.3 Ω, respectively, are connected in parallel. Calculate the emf and internal resistance of the equivalent cell.
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उत्तर
Given:
E1=1.5 V
E2=2 V
r1=0.2 Ω
r2 =0.3 Ω
The effective emf of two cells connected in parallel can be calculated as follows:
`E_(eff) = (E_1r_2+E_2r_1)/(r_1+r_2)`
`=> E_(eff) = (1.5xx0.3+2.0xx0.2)/0.5 = 1.7 V`
The effective resistance can be calculated as follows:
`R_(eff)= (r_1r_2)/(r_1+r_2)`
`=> R_(eff)= (0.2xx.03)/0.5`= 0.12 Ω
संबंधित प्रश्न
A battery of emf 12 V and internal resistance 2 Ω is connected to a 4 Ω resistor as shown in the figure.
(a) Show that a voltmeter when placed across the cell and across the resistor, in turn, gives the same reading.
(b) To record the voltage and the current in the circuit, why is voltmeter placed in parallel and ammeter in series in the circuit?
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