Physics 2010 | Study Mode

Join Discuss Share Question Share to WhatsApp
Question 31
A
low voltage 
B
steady voltage 
C
high pressure 
D
low pressure 
Explanation.
Share Answer pumping out of the gas in the discharge tube reduces the pressure inside the tube, therefore, electricity is conducted at low pressure

Correct Option:
D
Join Discuss Share Question Share to WhatsApp
Question 32
A
5.0 x 1016 Hz 
B
2.0 x 1016 Hz 
C
5.0 x 1015 Hz 
D
2.0 x 1015 Hz 
E
No correct option 
Explanation.
Share Answer E = hf
f = (E)/h = (5.44 x 10-19)/6.6 x 10-34 = 8.24 x 1014

Correct Option:
E
Join Discuss Share Question Share to WhatsApp
Question 33
A
rectification of signals 
B
conversion of a.c to d.c 
C
amplification of signals 
D
conversion of d.c to a.c 
Explanation.
Share Answer transistor serve the same purpose as triode valve, which is amplification of signals.

Correct Option:
C
Join Discuss Share Question Share to WhatsApp
Question 34
A
carbon 
B
silicon 
C
transistor 
D
phosphorus 
Explanation.
Share Answer A semiconductor is a material whose conductivity is between good conductor and insulator. Example of pure semi conductors are silicon and germanium

Correct Option:
B
Join Discuss Share Question Share to WhatsApp
Question 35
A
has no acceleration between point F and G 
B
decelerates between F and H 
C
has a constant soeed between points E and F 
D
Accelerates between points F and G 
Explanation.
Share Answer Above are the V-t graphs for
I Uniform acceleration
II uniform retardation
III Uniform velocity
Thus the car has no acceleration between point F and G since that portion of the graph represents uniform velocityPhy-explained-image

Correct Option:
A
Join Discuss Share Question Share to WhatsApp
Question 36
A
III, IV and VIII 
B
II, V and VIII 
C
III, VI and IX 
D
I, IV and VII 
Explanation.
Share Answer A bod y is said to be in stable equilibrium if after a slight displacement, the body returns to its former position. Thus, position III, VI and XI represents position of stable equilibrium

Correct Option:
C
Join Discuss Share Question Share to WhatsApp
Question 37
A
0.500 J 
B
0.250 J 
C
0.050 J 
D
0.025 J 
Explanation.
Share Answer

Length of the string
L = y + x = 0.5m
x = L - y
= distance moved in the direction of force (which is the weight) when the body is released But cos 60o = y/0.5
y = 0.5cos60 = 0.5 x 1/2 = 0.25
x = l - y = 0.5 - 0.25 = 0.25m
Work done = force x distance moved in the direction of force.
= 0.1 x 0.25 = 0.025J

Phy-explained-image

Correct Option:
D
Join Discuss Share Question Share to WhatsApp
Question 38
A
7:5 
B
5:7 
C
1:2 
D
2:1 
Explanation.
Share Answer Metals P, Q
original length lP, lQ
Increase in length lP, lQ
Linear expansivities P, Q
P/Q = 2/3 ; and lP/lQ = 3/4
But increase in length, l = l
lP = PlP
lQ = QlQ
lP = PlP = 2 x 3 = 1
lQQlQ342

Ratio of increase in length of P to Q = 1:2

Correct Option:
C
Join Discuss Share Question Share to WhatsApp
Question 39
A
400 ms-1 
B
4,000 ms-1 
C
8,000 ms-1 
D
160,000 ms-1 
Explanation.
Share Answer The velocity of sound in air, VT, where T is absolute temperature
Thus V = KT or K = V/T
V is independent of pressure and density at a fixed temperature.
V1/T1 = V2/T2
T1 = 16 + 273 = 289K, V1 = 340ms-1
T2 = 127 + 273 = 400K, V2 = ?
340 = V2
289400

V2 = 340400
_289

= 400m/s

Correct Option:
A
Join Discuss Share Question Share to WhatsApp
Question 40
A
2.52 x 10-6
B
6.90 x 10-6
C
2.52 x 10-4
D
6.90 x 10-4
Explanation.
Share Answer C = C1 + C2 + C3
= 2 + 4 + 8 = 14F
V = 6V
Energy = 1/2CV2
1/2 x 14 x 10-6 x 62
= 2.52 x 10-4 JPhy-explained-image

Correct Option:
C
Previous Page Next Page
Question Map
Quiz link
Share Physics 2010 with your friends
Share to WhatsApp Share Quiz CBT mode Study mode copy link