Semiconductor Electronic: Material, Devices And Simple Circuits — Physics STD 12 Science — Question

If two bulbs of wattage 25 and 100 respectively each rated at 220 volt are connected in series with the supply of 440 volt, then which bulbs will fuse

(a) 100 watt bulb

(b) 25 watt bulb

(c) None of them

(d) Both of them

The wavefronts of a light wave travelling in vacuum are given by x + y + z = c. The angle made by the direction of propagation of light with the X-axis is:

Which group among the following is insulator?

When light propagates in vacuum there is an electric field and a magnetic field. These fields.

In Bohr’s model electrons are revolving in a circular orbits around the nucleus called as:

Assertion   :   Anode of Coolidge tube gets heated up at time of emission of X-rays.

Reason      : The anode of Coolidge tube is made of a material of high melting point.

(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.

Ten electrons are equally spaced and fixed around a circle of radius R. Relative to V = 0 at infinity, the electrostatic potential V and the electric field E at the centre C are

(a) V ≠ 0  and  ≠ 0

(b) V ≠ 0 and

(c) V = 0 and

(d) V =  0  and

The electromagnetic waves do not transport

(a) Energy

(b) Charge

(c) Momentum

(d) Information

n identical bulbs, each designed to draw a power p from a certain voltage supply, are joined in series across that supply. The total power which they will draw is

(a)

(b) p/n

(c) p

(d) np