CBSE 11TH PHYSICS - Online Test

Answer : Option A
Explaination / Solution:

Given , T= π5s

amplitude, x= 0.5 m

mass , m = 10g=0.01kg ,as we know that:

 T=2πmk−−√π5=2π0.01k−−−√or k=1 N/m

The maximum force is obtained at the maximum displacement i.e . amplitude 

F=−k xF=−1(0.5)=−0.5N

The negative value of force shows the attractive nature.

Answer : Option A
Explaination / Solution:

The acceleration due to gravity due to a body at point P on the surface of earth is

g=GMR2    -(1)

Let the body is placed to point Q at a height h abovr the surface of earth, then acceleration due to gravity:

gh=GM(R+h)2  -(ii)

Dividing (i) & (ii), we get

ghg=R2(R+h)2$\frac{g_h}{}$

By simplifying and expanding through binomial theorem, we get

gh=g(1−2hR)

From above expression we can clearly say that with increase in altitiude h , the value of acceleration due to gravity decreases.

Answer : Option A
Explaination / Solution:

the slope of the x-t grpah will give you velocity. So, if u=0, the slope of graph at t=0 is 0.

for u>0 case, the initial slope is +ve and for negative u, the initial slope is negative now, s = ut + 0.5at2, where acceleration=a let initial position is x​​​​​​o,

x=x​​​​​​xo+ut+0.5at2 ,

Hence you will get parabolic shapes.

Answer : Option D
Explaination / Solution:
No Explaination.

Answer : Option A
Explaination / Solution:

the average speed of a particle (defined as total path length divided by the time taken to cover the path) is either greater or equal to the magnitude of average velocity of the particle over the same interval of time,

Answer : Option A
Explaination / Solution:

kinetic energy is transferred to other forms of energy—such as thermal energy, potential energy, and sound—during the collision process. After collision if recovery of kinetic energy is less than % then it is called inelastic collision i.e.. some part of kinetic energy is not recover. So that in an inelastic collision the total kinetic energy after the collision is less than before the collision

Answer : Option A
Explaination / Solution:
No Explaination.

Answer : Option D
Explaination / Solution:

It is impossible for a self acting machine unaided by any external agency to transfer heat from a cold to a hot reservior. In other words,heat by itself cannot pass from a colder to a hotter body.

Answer : Option C
Explaination / Solution:

F = mg = 0.05 x 10 = 0.5 N downwards

Answer : Option D
Explaination / Solution:

Earth and any body pull each other towards themselves , the force applied on both of them remaining the same , but the changes in position of an object is determined by its velocity and acceleration .