Dynamo is a device for converting
|
(a) Electrical energy into mechanical energy |
|
(b) Mechanical energy into electrical energy |
|
(c) Chemical energy into mechanical energy |
|
(d) Mechanical energy into chemical energy |
(b) Mechanical energy into electrical energy
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Wavelength of light of frequency 100Hz
|
(a) 2 |
(b) 3 |
(c) 4 |
(d) 5 |
A hydrogen like atom of atomic number Z is in an excited state of quantum number 2n. It can emit a maximum energy photon of 204 eV. If it makes a transition to quantum state n, a photon of energy 40.8 eV is emitted. The value of n will be
|
(a) 1 |
(b) 2 |
(c) 3 |
(d) 4 |
A conducting wire frame is placed in a magnetic field which is directed into the paper. The magnetic field is increasing at a constant rate. The directions of induced current in wires AB and CD are
|
(a) B to A and D to C |
(b) A to B and C to D |
|
(c) A to B and D to C |
(d) B to A and C to D |
An electron (charge q coulomb) enters a magnetic field of H 
with a velocity of vm/s in the same direction as that of the field the force on the electron is
|
(a) Hqv Newton’s in the direction of the magnetic field |
|
(b) Hqv dynes in the direction of the magnetic field |
|
(c) Hqv Newton’s at right angles to the direction of the magnetic field |
|
(d) Zero |
In the following reaction 
is
|
(a) 28 |
(b) 27 |
(c) 26 |
(d) 22 |
Three plates of common surface area A are connected as shown. The effective capacitance will be
|
(a) |
(b) |
(c) |
(d) |
