Study the diagram:
(a) Calculate the total resistance of the circuit.
(b) Calculate the current drawn from the cell.
(c) State whether the current through 10 Ω resistor is greater than, less than or equal to the current through the 12 Ω resistor.
Given, V = 4 V, R₁ = 10 Ω, R₂ = 6 Ω, R₃ = 12 Ω and R₄ = 4 Ω.
(a) R₁ + R₂ = 16 Ω and R₃ + R₄ = 16 Ω. These are in parallel.
\frac1{R_{eq}}=\frac1{16}+\frac1{16}=\frac2{16}Req = 8 Ω.
(b) Current = \frac{4}{8} = 0.5 A.
(c) Each branch carries 0.25 A. Hence, current through the 10 Ω resistor equals current through the 12 Ω resistor.
More ICSE Easy level questions
The voltage-current readings of a certain material are shown in the table given below: Voltage (V) Current (I) 10 V 2 A 20 V 3 A 30 V 4 A Study the table. (a) State whether the conductor used is ohmic or non-ohmic. (b) Justify your answer. (c) State Ohm’s law.
The specific resistance of a wire depends on: (a) its length (b) the material of the wire (c) its cross-sectional area (d) its radius
The potential difference between the terminals of a cell in a closed circuit is called: (a) terminal voltage (b) electromotive force (c) voltage drop (d) none of these
5 bulbs are connected in series in a room. One bulb is fused. It is removed and remaining 4 bulbs are again connected in series to the same circuit. What will be the effect on the following physical quantities? (Increases, Decreases, Remain Same) (a) Resistance (b) Intensity of light
(a) Define specific resistance. (b) What happens to the specific resistance of a conductor if its length is doubled? (c) Name a substance whose specific resistance remains almost unchanged with the increase in its temperature.
When a current I flows through a wire of resistance R for time t then the electrical energy produced is given by: (a) I2Rt (b) IR2t (c) IRt (d) IRt2
Find the value of current I drawn from the cell. (a) Calculate the current I. (b) Calculate the terminal voltage.
Three identical bulbs B1, B2 and B3, each of power rating 18 W, 12 V, are connected to a battery of 12 V as shown. (a) Calculate: (i) the resistance of each bulb (ii) the current drawn from the cell (b) If bulb B3 is removed from the circuit, will the brightness of bulb B1 increase, decrease or remain the same?
In a closed circuit containing a bulb and a cell, the electromotive force (ε) and the terminal voltage (V) is related as. (Given I is current and r is internal resistance.) (a) V = ε + Ir (b) V = ε – Ir (c) V = ε ÷ Ir (d) V = ε × Ir
Choose the correct relation for e.m.f. (ε) and terminal voltage V: (a) ε = V [always] (b) V > ε [always] (c) V < ε [when the cell is in use] (d) None of these
A resistance R is connected across a cell with a switch and a rheostat in series. A voltmeter is connected parallel across the cell. Current in the circuit is increased using the rheostat. (a) How will the voltmeter reading change? (increase / decrease / remain the same) (b) Justify your answer stated in (a) above.
A current flows through a metallic conductor for a long period of time. State the change you would expect in its: (a) Resistance (b) Resistivity
