CBSE 11TH PHYSICS - Online Test

Answer : Option A
Explaination / Solution:

P=WtW=mgh=50×9.8×443t=15×60secP=50×9.8×44315×60=241W

Answer : Option B
Explaination / Solution:

I=25(MR2)=25[(43πR3).ρ.R2]=25[(43227R3).ρ.R2]    As Mass =  Density x Volume of Sphere 

=176105ρR5

Answer : Option C
Explaination / Solution:

surface tension is measured in force per unit length. The S.I unit is newton per meter but the CGS unit dyne per centimeter is also used.

Answer : Option C
Explaination / Solution:

There are four fundamental forces in nature which are Gravitational force, Strong force, Weak force and Electromagnetic force.

Gravitational Force: This force is the weakest but has an infinite range.

Strong Nuclear force: This force holds the nucleus of an atom together. It is the strongest of the forces. It acts over a range of about 10-15m.

Weak Nuclear Force: This force is weak compared to the strong force as the name implies and has the shortest

range of 10-18m

Electromagnetic Force: This is the second strongest force after the strong force and it acts on electrically charged particles. It has strength of 1/137 relative to the strong force but has an infinite range.

Answer : Option D
Explaination / Solution:

Hydrogen is a diatomic gas. (CV = 2.5R)

Change in internal energy 

ΔU=nCVΔT=1×2.5×8.31×120=2493J=2.49KJ

 

Answer : Option C
Explaination / Solution:

number of moles according to gas equation

n=PVRT=100×100×10−68.31×293=4.10×10−6

Answer : Option D
Explaination / Solution:

Dimension of y = M​​​​​​0 L​​​​​​1 T0

Dimension of a = M0L​​1T​​​​​​0 

Dimension of sin2πtT$sin\frac{2\pi t}{T}$= M0L0T0$M^0{L}^0{T}^0$

Dimension of L.H.S = Dimension of R.H.S Hence, the given formula is dimensionally correct.

Answer : Option D
Explaination / Solution:
No Explaination.

Answer : Option B
Explaination / Solution:

Initial velocity u = 20.0 m/s

At maximum height it ll stop

So final velocity v = 0 m/s

Acceleration due to gravity g = 9.8 m/s​​​​​​2

Time taken to reach maximum height = t

We know

v = u + at

=> 0=20+(−9.8)t

=>t=−20−9.8=2.04 s [g is taken negative because it is in opposite direction of motion.]

Answer : Option C
Explaination / Solution:
No Explaination.