A cathode emits 1.8 
electrons per second, when heated. When 400V is applied to anode all the emitted electrons reach the anode. The charge on electron is 1.6 
. The maximum anode current is
|
(a) 2.7 μA |
(b) 29 μA |
(c) 72 μA |
(d) 29 μA |
(b) 29 μA
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The curve of binding energy per nucleon as a function of atomic mass number has a sharp peak for helium nucleus. This implies that helium
| (a) Can easily be broken up | (b) Is very stable |
| (c) Can be used as fissionable material | (d) Is radioactive |
Three capacitors each of capacitance 1μF are connected in parallel. To this combination, a fourth capacitor of capacitance 1μF is connected in series. The resultant capacitance of the system is
|
(a) 4μF |
(b) 2μF |
(c) |
(d) |
A capacitor when filled with a dielectric K = 3 has charge 
, voltage 
and field 
. If the dielectric is replaced with another one having K = 9 the new values of charge, voltage and field will be respectively
(a) 
|
(b) 
|
(c) |
(d) |
Electric current is due to drift of electrons in
| (a) Metallic conductors | (b) Semi-conductors | (c) Both (a) and (b) | (d) None of these |
An ammeter with internal resistance 90 Ω reads 1.85 A when connected in a circuit containing a battery and two resistors 700 Ω and 410 Ω in series. Actual current will be
|
(a) 1.85 A |
(b) Greater than 1.85 A |
|
(c) Less than 1.85 A |
(d) None of these |
