English Medium कक्षा १० - CBSE Question Bank Solutions for Science

A piece of wire of resistance R is cut into three equal parts. These parts are then connected in parallel. If the equivalent resistance of this parallel combination is R₁, what is the value of the ratio R₁ : R?

Study the following circuit:

On the basis of this circuit, answer the following questions:

i. Find the value of total resistance between the points A and B.

ii. Find the resistance between the points B and C.

iii. Calculate the current drawn from the battery, when the key is closed

OR

iii. In the above circuit, the 16Ω resistor or the parallel combination of two resistors of 8 Ω, which one of the two will have more potential difference across its two ends? Justify your answer.

Why is this mode practiced for growing some types of plants?

Bryophyllum can be propagated vegetatively by the ______ 

Vegetative propagation refers to formation of new plants from ______ 

In a potato, vegetative propagation takes place by ______ 

Vegetatively propagated plants ______ 

Which of the following is not an artificial method of vegetative propagation?

Name the reproductive and non-reproductive parts of bread mould (Rhizopus).

List two advantages of vegetative propagation technique.

A farmer wants to grow banana plants genetically similar enough to the plants already available in his field. Which one of the following methods would you suggest for this purpose?

The plants that can be raised by the method of vegetative propagation are ______.

Why does the cord of an electric heater not glow while the heating element does?

Compute the heat generated while transferring 96000 coulomb of charge in one hour through a potential difference of 50 V.

An electric iron of resistance 20 Ω takes a current of 5 A. Calculate the heat developed in 30 s.

An electric heater of resistance 8 Ω draws 15 A from the service mains 2 hours. Calculate the rate at which heat is developed in the heater.

Why is the tungsten used almost exclusively for filament of electric lamps?

Why are the conductors of electric heating devices, such as bread-toasters and electric irons, made of an alloy rather than a pure metal?

How does the resistance of a wire vary with its area of cross-section?

Write Joule's law of heating.