CBSE 11TH PHYSICS - Online Test

Answer : Option C
Explaination / Solution:

no. of molecule per unit volume 

nV=NV=PkT=1.01×1051.38×10−23×293=2.5×1025

mean free path  

λ=12√πd2nV=11.41×3.14×(2×10−2)2×2.5×1025=2.25×10−7m

Answer : Option D
Explaination / Solution:

for any temperature scale 

XXTr=const.TA200=TB350TA=47TB

Answer : Option A
Explaination / Solution:

Area of the house on the slide = 1.75 cm​​2

Area of the image of the house formed on the screen = 1.55 m​​​​​​2 = 1.55 × 104 cm​​​​​2

Arial magnification a​​​​​​m = Area of imagearea of object

= 1.55×1041.75= 8857

Linear magnification = am−−−√=8857−−−−√

= 94.1

Answer : Option B
Explaination / Solution:
No Explaination.

Answer : Option A
Explaination / Solution:

Let the distance traveled by the bus when man catch the bus be S meter distance traveled by the man when he catch the bus S'=S+48 meter

Given :

Initial velocity of bus u=0

Initial velocity of man u'=10m/sec Acceleration of Bus=1 m/s2 

Accelerationof Man=0

We will use formula for displacement

S=ut+12at2

By substituting the values in above equation we get,

Displacement of Bus S=12t2 ......(1)

Displacement of Man S+48=10t .......(2)

By substituting the value of S from eq(1) in eq(2)we get

12t2+48=10t

=>t2−20t+96=0

=>t2−12t−8t+96=0

=>(t−8)(t−12)=0

=> t = 8, 12

Taking minimum value t = 8 sec

Answer : Option A
Explaination / Solution:
No Explaination.

Answer : Option B
Explaination / Solution:

u = uxi + uyj = 10j,

ux = 0 and uy = 10 m/s

a = axi + ayj = 8i + 2j,

ax = 8 and ay = 2 m/s2

x = uxt +12axt2

=> 16 = 8t22

t = 2 sec         

y = uyt +  ayt22 = 10x2 + 2×222= 24 m

Answer : Option B
Explaination / Solution:
No Explaination.

Answer : Option B
Explaination / Solution:

work done by the gas is equal to area under P-V curve

Answer : Option B
Explaination / Solution:

At the mean position, the bob has a horizontal velocity. so when the string is cut, it will fall along a parabolic path under the effect of gravity.