GATE Questions

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The statements true about viruses are :

1. The capsid enters the host cell if the virus is enveloped.

2. Enveloped viruses bud from the host cell. 

3. HIV contains reverse transcriptase.

4. A retrovirus contains RNA.

The man has 12 sons and the 12 sons has each one sister.

=> 12 sons + 1 sister = 13 children.

We know, 

S.I = PTR/100 where P = principal amount, T = time, R = rate of interest

Here in the given data,

Interest for two years S.I = 924 - 812 = Rs. 112

Now, Principal amount P = 812 - 112 = Rs. 700 

Now,

R = S.I x 100/PT

R = 112 x 100/700 x 2

R = 11200/1400

R = 8%

Hence, the rate of interest R = 8%.

Cost price = Rs. 30

Selling price = Rs. 50

Gain = Rs. 20

Profit % = Gain/cost price x 100 = 20/50 x 100 = 40%

As you were asleep, none of the things could have happened without doing "open your eyes" first.

A redox reaction is a type of reaction which involves transfer of electrons among two species. This reaction is also called oxidation-reduction reaction.

In oxidation process, there is an increase in oxidation state of an atom, ion or molecule by losing the electrons.

In reduction process, there is a decrease in oxidation state of an atom, ion or molecule by accepting the electrons.

1)

In this reaction, Ba undergoes oxidation and Cl undergoes reduction.
This reaction is redox reaction.
In this reaction, oxidation number of Ba increases from 0 to +2 . So, Ba undergoes oxidation. The oxidation number of Cl decreases from 0 to -1. So, Cl undergoes reduction.

2) 

From this above reaction, it is clear that Aluminum undergoes oxidation and silver undergoes reduction.
Due to this, this reaction is redox reaction.

In this reaction, oxidation number of Aluminum increases from 0 to +1. So, aluminum undergoes oxidation. The oxidation number of silver decreases from +1 to 0. So, silver undergoes reduction.

3)

In this reaction, Mg undergoes oxidation and Br undergoes reduction.
This reaction is redox reaction.
The reactions 1, 3 and 4 are redox reactions.
In this reaction, oxidation number of Mg increases from 0 to +2 . So, Mg undergoes oxidation. The oxidation number of Br decreases from 0 to -1 . So, Br undergoes reduction.

Hence all the above reactions are redox reactions.

International day of sign language is celebrated annually across the world on 23rd september along with International Week of the Deaf.