Which radiation in sunlight, causes heating effect
|
(a) Ultraviolet |
(b) Infrared |
(c) Visible light |
(d) All of these |
Which radiation in sunlight, causes heating effect
|
(a) Ultraviolet |
(b) Infrared |
(c) Visible light |
(d) All of these |
(b) Infrared
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A particle moving in a magnetic field increases its velocity, then its radius of the circle
|
(a) Decreases |
(b) Increases |
(c) Remains the same |
(d) Becomes half |
A magnet is suspended in such a way that it oscillates in the horizontal plane. It makes 20 oscillations per minute at a place where dip angle is 30o and 15 oscillations per minute at a place where dip angle is 60o. The ratio of total earth's magnetic field at the two places is
|
(a) 3 |
(b) 16 : 9 |
(c) 4 : 9 |
(d) 2 |
A slit of width a is illuminated by white light. For red light (λ = 6500 Å), the first minima is obtained at θ = 30°. Then the value of a will be
|
(a) 3250 Å |
(b) 6.5 |
(c) 1.24 microns |
(d) 2.6 |
In the arrangement of resistances shown below, the effective resistance between points A and B is
|
(a) 20 Ω |
(b) 30 Ω |
(c) 90 Ω |
(d) 110 Ω |
denotes the mass of a proton and
that of a neutron. A given nucleus, of binding energy B, contains Z protons and N neutrons. The mass M(N, Z) of the nucleus is given by (c is the velocity of light)
|
(a) |
(b) |
|
(c) |
(d) |
Six charges, three positive and three negative of equal magnitude are to be placed at the vertices of a regular hexagon such that the electric field at O is double the electric field when only one positive charge of same magnitude is placed at R. Which of the following arrangements of charges is possible for P, Q, R, S, T and U respectively

|
(a) +, -, +, -, -, + |
(b) +, -, +, -, +, - |
(c) +, +, -, +, -, - |
(d) -, +, +, -, +, - |
In an LR-circuit, time constant is that time in which current grows from zero to the value (where
is the steady state current)
|
(a) |
(b) |
(c) |
(d) |