English Medium कक्षा १० - CBSE Question Bank Solutions for Science

An electric bulb of resistance 20 Ω and a resistance wire of 4 Ω are connected in series with a 6 V battery.
Draw the circuit diagram, and calculate:

(a) total resistance of the circuit.
(b) current through the circuit.
(c) potential difference across the electric bulb.
(d) potential difference across the resistance wire.

Three resistors are connected as shown in the diagram.

Through the resistor 5 ohm, a current of 1 ampere is flowing.

(i) What is the current through the other two resistors?
(ii) What is the p.d. across AB and across AC?
(iii) What is the total resistance

The circuit diagram given below shows the combination of three resistors R₁, R₂ and R₃: 

In the circuit diagram given below five resistances of 10 Ω, 40 Ω, 30 Ω, 20 Ω, and 60 Ω are connected as shown to a 12 V battery. 

Calculate:
(a) total resistance in the circuit. 

(b) total current flowing in the circuit.

In the circuit diagram  given below, three resistors R₁, R₂, and R₃ of 5 Ω, 10 Ω and 30 Ω, respectively are connected as shown 

Calculate:

1. current through each resistor.
2. total current in the circuit. 
3. total resistance in the circuit.

A p.d. of 6 V is applied to two resistors of 3 Ω and 6 Ω connected in parallel. Calculate:

(a) the combined resistance
(b) the current flowing in the main circuit
(c) the current flowing in the 3 Ω resistor. 

In the circuit shown below, the voltmeter reads 10 V. 

(a) What is the combined resistance?
(b) What current flows?
(c) What is the p.d. across 2 Ω resistor?
(d) What is the p.d. across 3 Ω resistor?

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?

The figure given below shows an electric circuit in which current flows from a 6 V battery through two resistors. 

1. Are the resistors connected in series with each other or in parallel?
2. For each resistors, state the p.d. across it.
3. The current flowing from the battery is shared between the two resistors. Which resistor will have bigger share of the current?
4. Calculate the effective resistance of the two resistors.
5. Calculate the current that flows from the battery.

(a) With the help of a circuit diagram, obtain the relation for the equivalent resistance of two resistances connected in parallel.
(b) In the circuit diagram shown below, find:

(i) Total resistance.
(ii) Current shown by the ammeter A 

A battery and three lamps are connected as shown: 

Which of the following statements about the currents at X, Y and Z is correct?
(a) The current at Z is greater than that at Y.
(b) The current at Y is greater than that at Z.
(c) The current at X equals the current at Y.
(d) The current at X equals the current at Z. 

V₁, V₂ and V₃ are the p.ds. across the 1Ω, 2Ω and 3Ω resistors in the following diagram, and the current is 5 A.  

Which one of the columns (a) to (d) shows the correct values of V₁, V₂ and V₃measured in volts? 

           `V_1`   `V_2`  `V_3` 

(a)         1.0       2.0        3.0                    

(b)         5.0       10.0      15.0

(c)         5.0       2.5        1.6                 

(d)         4.0       4.0        2.0 

You can given one hundred 1 Ω resistors. What is the smallest and largest resistance you can make in a circuit using these?

If the lamps are both the same in the figure given below and if A₁ reads 0.50 A, what do A₂, A₃, A₄ and A₅ read? 

What happens to the other bulbs in a series circuit if one bulb blows off?

What happens to the other bulbs in a parallel circuit if one bulb blows off?

Which type of circuit, series or parallel, is preferred while connecting a large number of bulbs: 

(a) for decorating a hotel building from outside?

Which type of circuit, series or parallel, is preferred while connecting a large number of bulbs:  

(b) for lighting inside the rooms of the hotel?

Draw a circuit diagram to show how two 4 V electric lamps can be lit brightly from two 2 V cells.

Give three reasons why different electrical appliances in a domestic circuit are connected in parallel.