Electrostatic Potential and Capacitance — Physics STD 12 Science — Question

A microscope is used with sodium light and its resolving power is not sufficiently large. Higher resolution will be obtained by using wavelength of:

Which of the following is used as standard for determination of atomic mass unit?

The de-Broglie wavelength associated with the particle of mass m moving with velocity v is

(a) h/mv

(b) mv/h

(c) mh/v

(d) m/hv

Photoelectric effect was successfully explained first by

(a) Planck

(b) Hallwash

(c) Hertz

(d) Einstein

When the wave of hydrogen atom comes from infinity into the first orbit then the value of wave number is

(a) 109700 cm–1

(b) 1097cm–1

(c) 109 cm–1

(d) None of these

The half-life of radioactive Polonium (Po) is 138.6 days. For ten lakh Polonium atoms, the number of disintegrations in 24 hours is

(a) 2000

(b) 3000

(c) 4000

(d) 5000

A capacitor with air as the dielectric is charged to a potential of  100 volts. If the space between the plates is now filled with a dielectric of dielectric constant 10, the potential difference between the plates will be

(a) 1000  volts

(b) 100 volts

(c) 10 volts

(d) Zero

E denotes electric field in a uniform conductor, I corresponding current through it,  drift velocity of electrons and P denotes thermal power produced in the conductor, then which of the following graph is incorrect

(a)

(b)

(c)

(d)

A condenser having a capacity of 6mF is charged to 100 V and is then joined to an uncharged condenser of 14 μF  and then removed. The ratio of the charges on 6mF  and 14mF  and the potential of 6mF will be

(a)  and 50 volt

(b)  and 30 volt

(c)  and 30 volt

(d)  and 0 volt

In a PN-junction diode not connected to any circuit

(a) The potential is the same everywhere

(b) The P-type is a higher potential than the N-type side

(c) There is an electric field at the junction directed from the N- type side to the P- type side

(d) There is an electric field at the junction directed from the P-type side to the N-type side