Question

Correct the given statements.

1. Autotrophs are green plants which can prepare their own food using water, nitrogen

and sunlight.

2. An increase in the amount of hydrogen and nitrogen lead to global warming.

3. The earliest form of democracy existed in the Rome.

4. Coins, monuments and buildings are the examples of Literary sources.

5. Biographies are self-written while Autobiographies are written by court chronicles.​

Answer 1

Answer:

Answer

Since the voltmeter reading shows 2 V. Thus V=2.

Also, Current send by electric cell =0.4 A

Thus I=0.4 A

By Ohm's law V=IR

⇒2=0.4×R

⇒R=

0.4

2

=

4

20

=5 Ω

Answer 2

Answer:

Given:-

Rate of descending the elevator = 7m/min

It start descend from 9 m above the ground level.

To Find:-

How long will it take to reach -205 m

Solution:-

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀According to the Question

It is given that elevator descends in to a mine shaft at the rate of 7m/min .If its descent starts from 9m above the ground level. we have to calculate the time taken to reach -205 m . So let's begin

As the elevator descend 9 m above from the ground level.

So , the distance descended by the elevator = -205 + (+9)

:\implies:⟹ -196m

Now it is given that the rate of descending the elevator is 7m/min. (we take the rate of descending in negative )

Let the time taken by the elevator be t min .

Therefore,

:\implies:⟹ rate = Distance/time

Substitute the value we get

:\implies:⟹ -7 = -196/t

:\implies:⟹ 7 = 196/t

:\implies:⟹ 7×t = 196

:\implies:⟹ t = 196/7

:\implies:⟹ t = 28 minutes

Hence, the time taken by the elevator is 28 minutes.