The wavelength of Red light in the visible region is about 760 nm. The energy of photon in that case will be :

An ordinary light of intensity \(I_0\) is passed through a polaroid \(P_1\) which is crossed with another polaroid \(P _{ 2 }\). Now a third polaroid is placed in between \(P _1\) and \(P _2\) with its pass aris making an angle \(\beta\) with the pass axis of \(P_1\). The value of \(\beta\) for which the intensity of light from \(P_2\) is \(\frac{I_0}{8}\) is :

Which of the following statements are correct:
A. In semiconductor diodes carriers are generated by photo-excitation.
B. When the photo diode is illuminated with light with energy (E) > Energy gap (Eg) of the semiconductor, then electron-holepairs are generated.
C. Photovoltaic devices convert electricity into optical radiation.
D. Photodiode can be used as a photodetector to detect optical signal.
E. Zener diode specification should be taken as per the required output voltage.
Choose the correct answer from the following options given below:

What will be the minimum length of antenna required to transmit a radio signal of frequency 10 MHz ?

Two solenoids each of length 7 m are placed co-axially, the outer solenoid has 1000 turns and the inner solenoid has 1200 turns. The diameter of the inner solenoid is 8 cm. The mutual inductance between the two solenoids is:

A potential difference of 6 V is applied across a conductor of length 12 cm. If the mobility of electrons is \( 5.6 \times 10^{-6} \text{ m}^2/\text{V}\cdot\text{s} \), their drift velocity will be:

Magnetic susceptibility \(X\) of a given material is \(- 0 . 5\). Identify the magnetic material.

For \(x>0\), the minimum value of \(\frac{x}{\log _e x}\) is

Kavya takes a personal loan of ₹ 10,00,000 at the rate of 12% per annum for 5 years, then the EMI by using flat rate method is:

Among the following, which alkyl halide has the highest boiling point?

If the system of equation
\(x-y+z=4\)
\(x-2 y-2 z=9\)
\(2 x+y+\lambda z=1\)
has a unique solution, then

Read the given passage and answer the following questions:
Secondary treatment or biological treatment: The primary effluent is passed into large tanks where air is pumped into it. This allows vigorous growth of aerobic microbes. While growing, these microbes consume the major part of the organic matter in the effluent. This significantly change the BOD (biochemical oxygen demand) of the effluent. The effluent in then passed into a tank a small part of the sludge is pumped back into the aeration tank to serve as the inoculum. The remaining major part of the sludge is pumped into large tanks called sludge digesters. Here, other kinds of bacteria grow anaerobically in the sludge. The biogas produced can be used source of energy as it is inflammable. The effluent from the secondary treatment plant is generally released into natural water bodies like rivers and streams.
Steps in primary treatment does not include:

If \(x_1, x_2, x_3,\)........,\(x_n\) are \(n\) observations in a sample then which of following is/are TRUE?
(A) The mean \(\bar{x}\) has \(n\) degree of freedom
(B) The mean \(\bar{x}\) has ( \(n-1\) ) degree of freedom
(C) The standard deviation of the sample has ( \(n-1\) ) degree of freedom
(D) The standard deviation of the sample has \(n\) degree of freedom
Choose the correct answer from the options given below :