The work function for metals A, B and C are respectively 1.92 eV, 2.0 eV and 5 eV. According to Einstein’s equation, the metals which will emit photo electrons for a radiation of wavelength 4100 Å is/are
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(a) None of these |
(b) A only |
(c) A and B only |
(d) All the three metals |
(c) A and B only
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A capacitor is used to store 24 watt hour of energy at 1200 volt. What should be the capacitance of the capacitor
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(a) 120 mF |
(b) 120 μF |
(c) 24 μF |
(d) 24 mF |
A 3volt battery with negligible internal resistance is connected in a circuit as shown in the figure. The current I, in the circuit will be
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(a) 1/3 A |
(b) 1 A |
(c) 1.5 A |
(d) 2 A |
The lowest frequency of light that will cause the emission of photoelectrons from the surface of a metal (for which work function is 1.65 eV) will be
|
(a) 4 |
(b) 4 |
(c) 4 |
(d) 4 |
Assertion : The mass of b-particles when they are emitted is higher than the mass of electrons obtained by other means.
Reason : b-particle and electron, both are similar particles.
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(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. |
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(d) If the assertion and reason both are false. |
A spherical condenser has inner and outer spheres of radii a and b respectively. The space between the two is filled with air. The difference between the capacities of two condensers formed when outer sphere is earthed and when inner sphere is earthed will be
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(a) Zero |
(b) 4π |
(c) 4π |
(d) 4 π |
Which of the following is not a mode of radioactive decay
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(a) Positron emission |
(b) Electron capture |
(c) Fusion |
(d) Alpha decay |
By placing the prism in minimum deviation position, images of the spectrum
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(a) Becomes inverted |
(b) Becomes broader |
(c) Becomes distinct |
(d) Becomes intensive |
