Nuclei — Physics STD 12 Science — Question

If a slab of insulating material 4   thick is introduced between the plates of a parallel plate capacitor, the separation between plates has to be increased by 3.5   to restore the capacity to original value. The dielectric constant of the material will be

(a) 6

(b) 8

(c) 10

(d) 12

If the voltage of X-ray tube is doubled, the intensity of X-rays will become

(a) Half

(b) Unchanged

(c) Double

(d) Four times

Assertion  :   The 200 W bulbs glows with more brightness then 100 W bulbs.

Reason    : A 100 W bulb has more resistance than a 200 W bulb.

(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.

(d) If the assertion and reason both are false.

In Young's double slit experiment, the distance between the two slits is 0.1 mm and the wavelength of light used is 4 . If the width of the fringe on the screen is 4 mm, the distance between screen and slit is

(a) 0.1 mm

(b) 1 cm

(c) 0.1 cm

(d) 1 m

What is the space around a current-carrying conductor, in which its magnetic effect can be experienced called?

Two bodies at different temperatures are mixed in a calorimeter. Which of the following quantities remains conserved?

1. Sum of the temperatures of the two bodies.
2. Total heat of the two bodies.
3. Total internal energy of the two bodies.
4. Internal energy of each body.

The example of non-ohmic resistance is:

In the following common emitter configuration an NPN transistor with current gain b = 100 is used. The output voltage of the amplifier will be

(a) 10 mV

(b) 0.1 V

(c) 1.0 V

(d) 10 V