English Medium कक्षा १० - CBSE Question Bank Solutions for Science

If the current I through a resistor is increased by 100% (assume that temperature remains unchanged), the increase in power dissipated will be:

In an electrical circuit, two resistors of 2 Ω and 4 Ω respectively are connected in series to a 6 V battery. The heat dissipated by the 4 Ω resistor in 5 s will be ______.

When a 4 Ω resistor is connected across the terminals of a 2 V battery, the number of coulombs passing through the resistor per second is:

Two electric bulbs have resistances in the ratio 1 : 2. If they are joined in series, the energy consumed in them is in the ratio:

The Salt Story

From: The New Indian Express 9 March 2021

The salt pans in Marakkanam, a port town about 120 km from Chennai are the third largest producer of salt in Tamil Nadu. Separation of salt from water is a laborious process and the salt obtained is used as raw materials for manufacture of various sodium compounds.

One such compound is Sodium hydrogen carbonate, used in baking, as an antacid and in soda acid fire extinguishers.

The table shows the mass of various compounds obtained when 1litre of sea water is evaporated.

How many grams of Magnesium Sulphate are present in 135g of solid left by evaporation of sea water?

The Salt Story

From: The New Indian Express 9 March 2021

The salt pans in Marakkanam, a port town about 120 km from Chennai are the third largest producer of salt in Tamil Nadu. Separation of salt from water is a laborious process and the salt obtained is used as raw materials for manufacture of various sodium compounds.

One such compound is Sodium hydrogen carbonate, used in baking, as an antacid and in soda acid fire extinguishers.

The table shows the mass of various compounds obtained when 1litre of sea water is evaporated.

What is the pH of the acid which is used in the formation of common salt?

Show how you would connect three resistors, each of resistance 6 Ω, so that the combination has a resistance of 4 Ω.

One of the constituents of baking powder is sodium hydrogencarbonate. The other constituent is :

How is an electric impulse created in human nervous system? 

Name the salt formed when sulphuric acid is added to sodium hydroxide and write its pH.

An aqueous solution of a salt turns blue litmus to red. The salt could be the one obtained by the reaction of ______.

Consider the following combinations of resistors:

1. 
   
2. 
   
3. 
   
4. 
   
   The combinations having equivalent resistance 1 Q is/are ______.

Trace the sequence of events which occur when you suddenly touch a hot object.

Think of situations where receptors do not work properly. What problems are likely to arise?

An electric lamp of 100 Ω, a toaster of resistance 50 Ω, and a water filter of resistance 500 Ω are connected in parallel to a 220 V source. What is the resistance of an electric iron connected to the same source that takes as much current as all three appliances, and what is the current through it?

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?