The frequency f of a wave is defined as the inverse of the period T:
The clock in the problem has a waveform with period
. Therefore, its frequency is
Answer:
∴The air cannot be made to flow in with the given pump at the given conditions.
Explanation:
Given:
- gauge pressure of bicycle tyre,
- length of cylinder of the pump,
- area of the the cylinder of the pump,
- we have the density of air at STP,
The piston must be pushed more than the pressure inside the tyre:
∴The air cannot be made to flow in with the given pump at the given conditions.
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.
Explanation:
object made of rubber, such as the ballons are elecrical insulators, meaning that they resist electric charges flowing through them..
when the ballon has been rubbed enough times to gain a sufficient negative charge, it will be attracted to the wall
That is red spectrum........................
