All categories

3 years ago

In Burglar alarm LDR acts as a/an a. off switch b. on switch c. AND gate d. OR gate

Physics

1 answer:

Gelneren [198K]3 years ago

4 0

In Burglar alarm, LDR acts an AND gate.

Answer: C

Explanation

The LDR is light dependent resistor. The principle used in the working of LDR is that the resistance is inversely proportional to the intensity of light falling on the diode.

In burglar alarm, LDR diode is combined with an IC 555.

Normally an LED source is made to be incident on the LDR diode with same intensity such that the resistance will be maintained constant.

As the LDR is connected with IC, the voltage will be high when light is falling on the diode.

The IC will give only two output states that is high and low. This confirms that LDR in burglar alarm act as AND gate.

As the thief enters and crosses the LED light, the intensity of the light falling on the diode will decrease leading to decrease in the voltage which will cause the alarm to beep.

You might be interested in

Mr. Claspell moves 100 N of avocados straight up 2.0 meters.

solniwko [45]

Answer:

see the various answers below

Explanation:

From the given details, we can see that we are required to solve for the work done.

1. Mr. Claspell moves 100 N of avocados straight up 2.0 meters.

Work done= Force*Distance

Work done= 100*2= 200Joules

2. The Flash tackles the Reverse-Flash and pushes him 3.0 meters using a force of 200 N.

Work done= Force*Distance

Work done= 200*3= 600Joules

3. Darth Vader moves a large rock using force. That force is 3.0 N and he moves the rock 15 meters.

Work done= Force*Distance

Work done= 3*15= 45Joules

4. Mario carries Princess Peach 45 meters away from Bowser’s Castle with a force of 5.0 N

Work done= Force*Distance

Work done= 5*45= 225Joules

5. A roller coaster car lifts a group of people 50 m to the top of the roller coaster with a force of 550 N.

Work done= Force*Distance

Work done= 550*50=27500Joules or 27.5kJ

6 0

3 years ago

Under what conditions does q, the heat evolved or absorbed by the system in a physical or chemical process, equal the change in

Paladinen [302]

Answer: When $w=-P\Delta V$

Explanation:

According to first law of thermodynamics, energy can neither be created nor be destroyed. It can only be transformed from one form to another.

$\Delta H=\Delta E+P\Delta V$

$\Delta E=q+w$

$\Delta H$ = change in enthalpy

P = pressure

$\Delta V$ = change in volume

$\Delta E$ =Change in internal energy

q = heat absorbed or released

w = work done on or by the system

$\Delta H=q+w+P\Delta V$

Thus for $\Delta E=q+w$ , $w=-P\Delta V$

The heat evolved or absorbed by the system in a physical or chemical process, equal the change in enthalpy of the system when $w=-P\Delta V$

8 0

4 years ago

A dog walks 100m at a bearing of 175 degrees. a) How far did it walk East?

LUCKY_DIMON [66]

1 kilometer

Explanation:

hope it helps

3 0

3 years ago

When an apple is cut, it often turns brown. What does the color change indicate?

IrinaK [193]

When an apple is cut (or bruised), oxygen is introduced into the injured plant tissue. When oxygen is present in cells, polyphenol oxidase (PPO) enzymes in the chloroplasts rapidly oxidize phenolic compounds naturally present in the apple tissues to o-quinones, colorless precursors to brown-colored secondary products. so it will be c

4 0

3 years ago

Read 2 more answers

Select the word that best completes the definition of microorganism. Microorganisms are typically ____-celled and consist of bac

Inga [223]

The correct word is single

4 0

3 years ago