A solid conducting sphere of radius R1 is surrounded by another concentric hollow conducting sphere of radius R2. The capacitance of this assembly is proportional to
|
(a) |
(b) |
(c) |
(d) |
(d) 
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According to the Rutherford’s atomic model, the electrons inside the atom are
|
(a) Stationary |
(b) Not stationary |
(c) Centralized |
(d) None of these |
As the intensity of incident light increases
|
(a) Photoelectric current increases |
|
(b) Photoelectric current decreases |
|
(c) Kinetic energy of emitted photoelectrons increases |
|
(d) Kinetic energy of emitted photoelectrons decreases |
If a long hollow copper pipe carries a direct current, the magnetic field associated with the current will be
|
(a) Only inside the pipe |
(b) Only outside the pipe |
|
(c) Neither inside nor outside the pipe |
(d) Both inside and outside the pipe |
Two voltameters, one of copper and another of silver, are joined in parallel. When a total charge q flows through the voltameters, equal amount of metals are deposited. If the electrochemical equivalents of copper and silver are 
and 
respectively the charge which flows through the silver voltameter is
|
(a) |
(b) |
(c) |
(d) |
A dry cell has an e.m.f. of 1.5 V and an internal resistance of 0.05Ω. The maximum current obtainable from this cell for a very short time interval is
|
(a) 30 A |
(b) 300 A |
(c) 3 A |
(d) 0.3 A |
The ray diagram could be correct
|
(a) If |
(b) If |
|
(c) If |
(d) Under no circumstances |
A 4 mF condenser is charged to 400 V and then its plates are joined through a resistance. The heat produced in the resistance is
|
(a) 0.16 J |
(b) 0.32 J |
(c) 0.64 J |
(d) 1.28 J |
Assertion : Self-inductance is called the inertia of electricity.
Reason : Self-inductance is the phenomenon, according to which an opposing induced e.m.f. is produced in a coil as a result of change in current or magnetic flux linked in the coil.
|
(a) If both assertion and reason are true and the reason is the correct explanation of the assertion. |
|
(b) If both assertion and reason are true but reason is not the correct explanation of the assertion. |
|
(c) If assertion is true but reason is false. |
|
(d) If the assertion and reason both are false. |
