A rectangular loop with a sliding connector of length l = 1.0 m is situated in a uniform magnetic field B = 2T perpendicular to the plane of loop. Resistance of connector is r = 2W. Two resistance of 6W and 3W are connected as shown in figure. The external force required to keep the connector moving with a constant velocity v = 2m/s is
|
(a) 6 N |
(b) 4 N |
(c) 2 N |
(d) 1 N |
(c) 2 N
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A rocket is going towards moon with a speed v. The astronaut in the rocket sends signals of frequency v towards the moon and receives them back on reflection from the moon. What will be the frequency of the signal received by the astronaut (Take v << c)
|
(a) |
(b) |
(c) |
(d) |
The danger signals installed at the top of tall buildings are red in colour. These can be easily seen from a distance because among all other colours, the red light:
The energy of hydrogen atom in its ground state is – 13.6 eV. The energy of the level corresponding to the quantum number n is equal 5 is
|
(a) – 5.40 eV |
(b) – 2.72 eV |
(c) – 0.85 eV |
(d) – 0.54 eV |
The energy stored in the condenser is
|
(a) QV |
(b) |
(c) |
(d) |
