English Medium Class 10 - CBSE Question Bank Solutions

What are the advantages of connecting electrical devices in parallel with the battery instead of connecting them in series?

How can three resistors of resistances 2 Ω, 3 Ω and 6 Ω be connected to give a total resistance of 4 Ω ?

How many 176 Ω resistors (in parallel) are required to carry 5 A on a 220 V line?

Show how you would connect three resistors, each of resistance 6 Ω, so that the combination has a resistance of 9 Ω.

Several electric bulbs designed to be used on a 220 V electric supply line are rated 10 W. How many lamps can be connected in parallel with each other across the two wires of 220 V line if the maximum allowable current is 5 A?

A hot plate of an electric oven connected to a 220 V line has two resistance coils A and B, each of 24 Ω resistances, which may be used separately, in series, or in parallel. What are the currents in the three cases?

Write the molecular formula of first two members of homologous series having functional group -Cl.

Write the molecular formula of first two members of homologous series having functional group −Br.

Write the molecular formula of first two members of homologous series having functional group – OH

The following vegetables are kept in a basket :

Potato, Tomato, Radish, Brinjal, Carrot, Bottle-gourd

Which two of these vegetables correctly represent the homologous structures?

(A) Carrot and Tomato

(B) Potato and Brinjal

(C) Radish and Carrot

(D) Radish and Bottle-gourd

Write the molecular formula of the 2^nd and 3^rd member of the homologous series where the first member is ethyne.

Show how would you join three resistors, each of resistance 9 Ω so that the equivalent resistance of the combination is 

1) 13.5 

2) 6 Ω

State the law of combination of resistances in parallel.

Show how you would connect two 4 ohm resistors to produce a combined resistance of (a) 2 ohms (b) 8 ohms.

Which of the following arrangement, A or B, has the lower combined resistance? 

Find the current in each resistor in the circuit shown below: 

Explain with diagram what is meant by the "series combination" and "parallel combination" of resistances. In which case the resultant resistance is : (i) less, and (ii) more, than either of the individual resistances?

Two resistors, with resistance 5 Ω and 10 Ω respectively are to be connected to a battery of emf 6 V so as to obtain:

(i) minimum current flowing
(ii) maximum current flowing
(a) How will you connect the resistances in each case?
(b) Calculate the strength of the total current in the circuit in the two cases.

A resistor has a resistance of 176 ohms. How many of these resistors should be connected in parallel so that their combination draws a current of 5 amperes from a 220 volt supply line?