Focal length of a plane mirror is
|
(a) Zero |
(b) Infinite |
(c) Very less |
(d) Indefinite |
Focal length of a plane mirror is
|
(a) Zero |
(b) Infinite |
(c) Very less |
(d) Indefinite |
(b) Infinite
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In Bohr model of hydrogen atom, the ratio of periods of revolution of an electron in n = 2 and n = 1 orbits is
|
(a) 2 : 1 |
(b) 4 : 1 |
(c) 8 : 1 |
(d) 16 : 1 |
Resistances of 6 ohm each are connected in the manner shown in adjoining figure. With the current 0.5 ampere as shown in figure, the potential difference is
|
(a) 3.6 V |
(b) 6.0 V |
(c) 3.0 V |
(d) 7.2 V |
Two condensers of capacities 2C and C are joined in parallel and charged upto potential V. The battery is removed and the condenser of capacity C is filled completely with a medium of dielectric constant K. The p.d. across the capacitors will now be
|
(a) |
(b) |
(c) |
(d) |
An under water swimmer is at a depth of 12 m below the surface of water. A bird is at a height of 18 m from the surface of water, directly above his eyes. For the swimmer the bird appears to be at a distance from the surface of water equal to (Refractive Index of water is 4/3)
|
(a) 24 m |
(b) 12 m |
(c) 18 m |
(d) 9 m |
Two electric lamps of 40 watt each are connected in parallel. The power consumed by the combination will be
|
(a) 20 watt |
(b) 60 watt
|
(c) 80 watt |
(d) 100 watt |
Hydrogen atoms are excited from ground state of the principal quantum number 4. Then the number of spectral lines observed will be
|
(a) 3 |
(b) 6 |
(c) 5 |
(d) 2 |