Question

As Head Boy of your school write a speech to be delivered in the school assembly on the Importance of Reading in aboutl50-200 words.

Answer 1

Good morning, respected Principal, teachers and my dear friends! Today I am going to talk to you about the importance of reading.

Reading has at all times and in all ages been a great source of knowledge. It has many benefits.

Reading skills are essential to succeed in society. Those who are good readers tend to exhibit progressive social skills. A person who is an avid reader is able to mix with others. He is a better conversationalist than those who do not read. He can stand his ground. Reading broadens one’s horizons. It is in a way a substitute for travel. It is not possible to travel as much as one would like to but reading can fill in the gap created by the lack of travel.

Confidence in reading only comes from the daily practice of reading. A good reader can interact with others in a far better way because reading has widened his vision and point of view. Thus a widely-read man is a better conversationalist and is able to understand other’s point of view. It also helps to think rationally and analytically.

Those who are habitualed to reading feel comforted with books. It soothes and relieves tension and loneliness. Medically it also plays a vital role in eradicating depression and unrest. 

I hope all of you will cultivate the habit of reading regularly to reap its many benefits.

Answer 2

Comparison of emf of two cells with a potentiometer: 

To compare the emf of two cells, the circuit connections are made as shown in figure. Potentiometer wire CD is connected to a battery Bt and a key K in series. This is the primary circuit. The end C of the wire is connected to the terminal M of a DPDT (Double Pole Double Throw) switch and the other terminal N is connected to a jockey through a galvanometer G and a high resistance HR. The cells whose emf ξ and ξ to be compared are connected to the terminals M₁ N₁ and M₂, N₂ of the DPDT switch.

The positive terminals of Bt, ξ₁ and ξ₂ should be connected to the same end C. The DPDT switch is pressed towards M₁, N₁ so that cell ξ₁ is included in the secondary circuit and the balancing length l₁ is found by adjusting the jockey for zero deflection, Then the second cells ξ₂ is included in the circuit and the balancing length l₂ is determined. Let r be the resistance per unit length of the potentiometer wire and I be the current flowing through the wire

we have.

ξ₁ = Irl₁ …… (1) 

ξ₂ = Irl₂ ……. (2)

By dividing (1) by (2)

\(\frac {ξ^1}{ξ^2}\) = \(\frac{l^1}{l^2}\) ......... (3)

By including a rheostat (Rh) in the primary circuit, the experiment can be repeated several times by changing the current flowing through it.