Electrostatic Potential and Capacitance — Physics STD 12 Science — Question

Two wires of the same material and equal length are joined in parallel combination.  If one of them has half the thickness of the other and the thinner wire has a resistance of 8 ohms, the resistance of the combination is equal to

(a)

(b)

(c)

(d)

Consider the points lying on a straight line joining two fixed opposite charges. Between the charges there is

(a) No point where electric field is zero

(b) Only one point where potential is zero

(c) Only one point where electric field is zero

(d) a, b

Can a metal be used as a medium for dielectric

(a) Yes

(b) No

(c) Depends on its shape

(d) Depends on dielectric

There is an electric field E in X-direction. If the work done on moving a charge 0.2 C through a distance of 2 m  along a line making an angle 60°  with the X-axis is 4.0, what is the value of E

(a) N/C

(b) 4 N/C

(c) 5 N/C

(d) None of these

A charge of 40 μC  is given to a capacitor having capacitance C = 10 μF. The stored energy in ergs is

(a) 80

(b) 800

(c) 80

(d) 8000

The relation between voltage sensitivity () and current sensitivity () of a moving coil galvanometer is (Resistance of Galvanometer = G)

(a)

(b)

(c)

(d)

The rubber used in the wheels of aero-plane is _________?

A source of sound moves towards an observer.

1. The frequency of the source is increased.
2. The velocity of sound in the medium is increased.
3. The wavelength of sound in the medium towards the observer is decreased.
4. The amplitude of vibration of the particles is increased.

The minimum amount of energy required to emit electrons from a metal surface is called:

In a Bainbridge mass spectrometer positive rays of the same element produce different traces. The traces correspond to: