Electric Charges and Fields — Physics STD 12 Science — Question

A galvanometer of 25 W resistance can read a maximum current of 6mA.  It can be used as a voltmeter to measure a maximum of 6 V by connecting a resistance to the galvanometer.  Identify the correct choice in the given answers

(a) 1025 W in series

(b) 1025 W in parallel

(c) 975 W in series

(d) 975 W in parallel

How does the potential difference change with the effect of the dielectric when the battery is kept disconnected from the capacitor?

In the circuit given, the correct relation to a balanced Wheatstone bridge is

(a)

(b)

(c)

(d) None of these

For the photoelectric effect, the maximum kinetic energy  of the emitted photoelectrons is plotted against the frequency n of the incident photons as shown in the figure. The slope of the curve gives

(a) Charge of the electron

(b) Work function of the metal

(c) Planck's constant

(d) Ratio of the Planck’s constant to electronic charge

The energy gap in case of which of the following is less than 3eV?

A plane electromagnetic wave is incident on a material surface. The wave delivers momentum p and energy E.

Absorption of X-ray is maximum in which of the following different sheets

(a) Copper

(b) Gold

(c) Beryllium

(d) Lead

Which of the following is used for the formation of thermistor?

Equal charges are given to two spheres of different radii. The potential will

(a) Be more on the smaller sphere

(b) Be more on the bigger sphere

(c) Be equal on both the spheres

(d) Depend on the nature of the materials of the spheres

A coil having 500 square loops each of side 10 cm is placed normal to a magnetic flux which increases at the rate of 1.0 tesla/second. The induced e.m.f. in volts is

(a)  0.1

(b) 0.5

(c)  1

(d) 5