English Medium इयत्ता १० - CBSE Question Bank Solutions for Science

Define 1 kilowatt hour. 

Define electric power. An electrical device of resistance R is connected across a source of voltage V and draws a current I. Derive an expression for power in terms of current and resistance.

Unit of electric power may also be expressed as:

The unit of e.m.f. of a cell is ____________.

1 kWh is equal to:

A cooler of 1500 W, 200 volts and a fan of 500 W, 200 volts are to be used from a household supply. The rating of fuse to be used is:

1 mV is equal to:

Electric power is inversely proportional to ____________.

What is the commercial unit of electrical energy?

1 kWh = ____________

Compare the power used in the 2 Ω resistor in each of the following circuits:

1. a 6 V battery in series with 1 Ω and 2 Ω resistors
2. a 4 V battery in parallel with 12 Ω and 2 Ω resistors.

What is the meaning of electric power of an electrical device? Write its SI unit.

A student wants to use an electric heater, an electric bulb and an electric fan simultaneously.

How should these gadgets be connected with the mains? Justify your answer giving three reasons.

Give the structural formula of ethanol.

A carbon compound 'P' on heating with excess conc. H₂SO₄ forms another carbon compound 'Q' which on addition of hydrogen in the presence of nickel catalyst forms a saturated carbon compound 'R'. One molecule of 'R' on combustion forms two molecules of carbon dioxide and three molecules of water. Identify P, Q and R and write chemical equations for the reactions involved

Name the compound formed when ethanol is heated in excess of conc. sulphuric acid at 443 K. Also, write the chemical equation of the reaction stating the role of conc. sulphuric acid in it. What would happen if hydrogen is added to the product of this reaction in the presence of a catalyst such as palladium or nickel?

Write the name and structural formula of the compound obtained when ethanol is heated at 443 K with excess of conc. H₂SO₄. Also write chemical equation for the reaction stating the role of conc. H₂SO₄ in it.

How would you distinguish experimentally between an alcohol and a carboxylic acid?

How can ethanol and ethanoic acid be differentiated on the basis of their physical properties?