While using an electric bulb, the reflection for street lighting should be from
|
(a) Concave mirror |
(b) Convex mirror |
(d) Parabolic mirror |
(d) Parabolic mirror |
(b) Convex mirror
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Radius of 
nucleus is 3 Fermi. The radius of 
nucleus will be
|
(a) 5 Fermi |
(b) 6 Fermi |
(c) 11.16 Fermi |
(d) 8 Fermi |
Two spheres A and B of radius 4cm and 6cm are given charges of 80 μC and 40 μC respectively. If they are connected by a fine wire, the amount of charge flowing from one to the other is
|
(a) 20 μC from A to B |
(b) 16 μC from A to B |
|
(c) 32 μC from B to A |
(d) 32 μC from A to B |
The potential energy of a particle of mass m is given by
U(x) = 
l1 and l2 are the de-Broglie wavelengths of the particle, when 0 £ x £ 1 and x > 1 respectively. If the total energy of particle is 2E0, the ratio 
will be
|
(a) 2 |
(b) 1 |
(c) |
(d) |
Three capacitors of 2μF, 3μF and 6μF are joined in series and the combination is charged by means of a 24 volt battery. The potential difference between the plates of the 6 μF capacitor is
|
(a) 4 volt |
(b) 6 volt |
(c) 8 volt |
(d) 10 volt |
A polaroid is placed at 45o to an incoming light of intensity 
. Now the intensity of light passing through polaroid after polarisation would be
|
(a) |
(b) |
(c) |
(d) Zero |
The activity of a radioactive sample is measured as 9750 counts per minute at t = 0 and as 975 counts per minute at t = 5 minutes. The decay constant is approximately
|
(a) 0.230 per minute |
(b) 0.461 per minute |
|
(c) 0.691 per minute |
(d) 0.922 per minute |
A 2 MeV proton is moving perpendicular to a uniform magnetic field of 2.5 tesla. The force on the proton is
|
(a) 2.5 |
(b) 7.6 |
(c) 2.5 |
(d) 7.6 |
