Advertisements
Advertisements
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.
Advertisements
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
Distinguish between emf and terminal voltage of a cell.
A battery of emf 10 V and internal resistance 3 Ω is connected to a resistor. If the current in the circuit is 0.5 A, what is the resistance of the resistor? What is the terminal voltage of the battery when the circuit is closed?
A 10 V cell of negligible internal resistance is connected in parallel across a battery of emf 200 V and internal resistance 38 Ω as shown in the figure. Find the value of current in the circuit.
A cell of emf E and internal resistance r is connected to two external resistance R1 and R2 and a perfect ammeter. The current in the circuit is measured in four different situations:
(i) without any external resistance in the circuit
(ii) with resistance R1 only
(iii) with R1 and R2 in series combination
(iv) with R1 and R2 in parallel combination
The currents measured in the four cases are 0.42 A, 1.05 A, 1.4 A and 4.2 A, but not necessarily in the order. Identify the currents corresponding to the four cases mentioned above.
Find the equivalent resistance of the network shown in the figure between the points a and b.
How many time constants will elapse before the power delivered by a battery drops to half of its maximum value in an RC circuit?
A conductor of length ‘l’ is rotated about one of its ends at a constant angular speed ‘ω’ in a plane perpendicular to a uniform magnetic field B. Plot graphs to show variations of the emf induced across the ends of the conductor with
- angular speed ω and
- length of the conductor l.
A cell of emf E and internal resistance r is connected across an external resistance R. Plot a graph showing the variation of P.D. across R, versus R.
A battery of EMF 10V sets up a current of 1A when connected across a resistor of 8Ω. If the resistor is shunted by another 8Ω resistor, what would be the current in the circuit? (in A)
A cell of emf E is connected across an external resistance R. When current 'I' is drawn from the cell, the potential difference across the electrodes of the cell drops to V. The internal resistance 'r' of the cell is ______.
