A string of length L and force constant K is
stretched to obtain extension l. It is further
stretched to obtain extension
Indicate the direction of frictional force on a car
which is moving along the curved path with non
zero tangential acceleration; in anti-clock direction:
(a)
A rocket of mass 1000kg is to be projected vertically
upwards. The gases are exhausted vertically
downwards with velocity
l 1 .The work done in
second stretching is
(a) 12
1
2
Kl (b) 12 2
1
2
K l l
(c)
2 2
1
1
2
K l l (d) 1 1
1
2
2
Kl l l
(b)
(c) (d)
100 ms^1 with respect to
the rocket. What is the minimum rate of burning of
fuel, so as to just lift the rocket upwards against
the gravitation attraction? (take,g 10 ms^2 )
(a) 50 kg/s (b) 100 kg/s
(c) 200 kg/s (d) 400 kg/s
An adiabatic cylindrical tube is fitted with an
adiabatic separator as shown in figure. Initially
separator is in equilibrium and divides a tube in
two equal parts. The separator can be slide into
the tube by an external mechanism. An ideal gas
(1.5) is injected in the two sides at equal
pressures and temperatures. Now separator is slide
to a position where it divides the tube in the ratio 7
: 3. Find the ratio of the temperatures in the two
parts of the vessel.
(a) 3 : 2 (b) 1 : 2
(c) 3 : 7 (d) 7 : 3
To generate a power of 3.2 megawatt, the number
of fissions of U^235 per minute is
(Energy released per fission = 200 MeV,
1eV 1.6 10 ^19 J)
(a) 6 10^17 (b) 6 10^18
(c) 5 10^14 (d) 5 10^12
A potential barrier of 0.5V exists across a p-n
junction. If the width of depletion layer is 10-6m,
then intensity of electric field in this region will be
(a) 1 106 V/m (b) 5 105 V/m
(c) 4 104 V/m (d) 2 106 V/m
In a zener regulated power supply of a zener diode
with z
A radiation of 200W is incident on a surface which
is 60% reflecting and 40% absorbing.The total force
on the surface is
(a)^6
V 6V is used for regulation. The load
current is to be 4 mA and the unregulated input is
10V. The value of series resistor Rsis
(a) Infinite (b) Greater than 100
(c) Zero (d) Less than^5
1.07 10 N (b) 1.07 10 N ^7
(c) 1.03 10 N ^7 (d) 1.3 10 N ^6
The amplitude modulated current is given by
i125 1 0.6sin 2900 sin10 . t^6 tThe depth of
modulation is
(a) 60% (b) 6% (c) 36% (d) 66%
White light is incident on face
19.
20.
21.
22.
23.
- AB of a glass prism.
The path of the green component is shown
in the figure. If the green light is just totally
internally reflected at face AC as shown, the light
emerging from face AC will contain
(a) Violet, indigo and blue colours
(b) All colours
(c) Yellow, orange and red colours
(d) All colours except green
