Answer:
A). A Lever and Wheel and Axle.
Explanation:
1. A wheel axle is most obvious, as the wheels are connected via a chain and axle with spokes. This helps keep the wheels moving forward with less effort than walking.
2. A Lever is used to help Balance you as you ride the bike. Without it, you would tip over, and lose all the momentum you had gained up until that point.
3. (I took the test on e2020)
Answer:

Explanation:
We are given that
Current=I=1.75 A
Resistance =R=55.4 ohm
Time=t=9.5 min=
1 min=60 s
We have to find the heat generated by the resistor.
We know that
Heat=E=
Using the formula
Heat,
Hence, the heat generated by the resistor =
Three quarters remain un-decayed
Answer:
stored in a state of readiness.
Explanation:
Potential energy is stored in a state of readiness.
Potential energy can be defined as an energy possessed by an object or body due to its position.
Mathematically, potential energy is given by the formula;

Where, P.E represents potential energy measured in Joules.
m represents the mass of an object.
g represents acceleration due to gravity measured in meters per seconds square.
h represents the height measured in meters.
Answer:
B) 8 T.
Explanation:
For an ideal gas , the gas law that it follow is as follows
P₁V₁ / T₁ = P₂ V₂ /T₂
This law is followed by all the gases whether mono atomic or diatomic.
In this case following information are given
P₂ / P₁ = 3
V₂ / V₁ = 3
T₁ = T
T₂ = ?
From the gas law formula given , we have


= 3 X 3 T
= 9 T
Change in temperature = 9T - T = 8 T.