A square loop, carrying a steady current \(I,\) is placed in a horizontal plane near a long straight conductor carrying a steady current \(I_1\) at a distance \(d\) from the conductor as shown in the figure. The loop will experience:

The threshold frequency for a photosensitive metal is \(3.3\times10^{14}~\text{Hz}.\) If the light of frequency \(8.2\times10^{14}~\text{Hz}\) is incident on this metal, the cutoff voltage for the photoelectric emission will be:

An electron in the hydrogen atom jumps from the excited state \(n\) to the ground state. The wavelength so emitted illuminates a photosensitive material having a work function of \(2.75\text{ eV}.\) If the stopping potential of the photoelectron is \(10\text{ V},\) then the value of \(n\) is:
1. \(2\)
2. \(3\)
3. \(4\)
4. \(5\)

Two radioactive nuclei P and Q, in a given sample decay into a stable nucleus R. At time t = 0, number of P species are 4 ${\mathrm{N}}_0$ and that of Q are ${\mathrm{N}}_0$. The half-life of P (for conversion to R) is 1 minute whereas that of Q is 2 minutes. Initially, there are no nuclei of R present in the sample. When the number of nuclei of P and Q are equal, the number of nuclei of R present in the sample would be:
1. $2{\mathrm{N}}_0$
2. $3{\mathrm{N}}_0$
3. $\frac{9{\mathrm{N}}_0}{2}$
4. $\frac{5{\mathrm{N}}_0}{2}$

Out of the following which one is not possible energy for a photon to be emitted by hydrogen atom according to Bohr's atomic model?

1. 0.65 eV

2. 1.9 eV

3. 11.1 eV

4. 13.6 eV

A Zener diode, having a breakdown voltage equal to \(15~\text V,\) is used in a voltage regulator circuit as shown in the figure. The current through the diode is:

1. \(5~\text{mA}\)
2. \(10~\text{mA}\)
3. \(15~\text{mA}\)
4. \(20~\text{mA}\)

(a)
(b)
(c)
(d)

1. (a), (b) and (d)
2. (c) only
3. (a) and (c)
4. (b) and (d)