(d) Component of C
along A
-component of
D
along A
A motor cycle engine delivers a power 10 kW, by
consuming petrol at the rate of 2.4 kg/hour. If the
calorific value of petrol is 35.5 MJ/kg, the rate of
heat rejection by the exhaust is
(a) 13.7 kW (b) 5.5 kW
(c) 9.7 kW (d) 11.2 kW
Calculate the change in entropy when 1g of ice at
0 C is heated to water at 40 C
fus water
1
80 ,
cal g
L C
g C
(a) 0.42cal C ^1 (b) 0.28 /cal C
(c) 1.411 /cal C (d) None of these
A cylindrical capacitor has charge Q and length L.
If both the charge and length of the capacitor are
doubled, by keeping other parameters fixed, the
energy stored in the capacitor
(a) Increases two times
(b) Increases in four times
(c) Remains same
(d) Decreases two times
Velocity of the particle at x 3 cm and at
1
sec
8
t
is
(a) 50 /cm s (b) 120 /cm s
(c) 160 /cm s (d) 200 /cm s
A massless rod is suspended by two identical
strings AB and CD of equal length. A block of mass
m is suspended from point O such that BO is equal
to ‘x’Further, it is observed that the frequency of
(a) L/4 (b) L/5 (c) 4L/5 (d) 3L/
Figure shows a stretched string of length L and
pipes of length
Consider two sound sources
1 st harmonic (fundamental frequency) in AB is
equal to 2 nd harmonic frequency in CD. Then,
length of BO is
(a) Zero (b) 2 (c) 3 (d) 4
A train has just completed a U-curve in a track
which is a semicircle. The engine is at the forward
end of the semi circular part of the track while the
last carriage is at the rear end of the semicircular
track. The driver blows a whistle of frequency 200
Hz. Velocity of sound is 340 m/sec. Then the
apparent frequency as observed by a passenger in
the middle of a train when the speed of the train is
30 m/sec is
(a) 288 Hz (b) 209 Hz (c) 181 Hz (d) 200 Hz
In Young’s double slit experiment, fringe of width
2
2 2
L L
L, L, and in options (a),
(b),(c) and (d) respectively. The strings tension is
adjusted until the speed of waves on the string
equals the speed of sound waves in the air. The
fundamental mode of oscillation is then set up on
the string. In which pipe will the sound produced
by the string cause resonance?
(a) (b)
(c) (d)
S 1 and S 2 having
same frequency 100 Hz and the observer O located
between them. All the three are moving with same
velocity in same direction. The beat frequency as
heard by the observer is
are produced on a screen kept at a distance of 1
m from the slit. When the screen is moved away by
5 10 ^2 m, fringe width changes by 3 10 ^5 m. The
separation between the slits is 1 10 ^3 m. The
wavelength of the light used is ...nm
(a) 600 (b) 400 (c) 700 (d) 500
A
22.
23.
24.
25.
- 6000Å H line emitted by hydrogen in a star is
