NUMS 2020 PAPER

1. For gaining an atomic spectra, an evacuated glass tube it filled with:

2. During production of x-rays the cathode and anode are enclosed inside an evacuated glass chamber and high DC voltage of the order of:

3. Half-life of iodine-131 is 8 days. If 20mg is present initially. how much Iodine is left behind after 2 half-lives

4. 4.5 x 10^9 years the half-life of:

5. When a charge “Q” on a capacitor Is doubled then energy stored “U” will:

6. By increasing area of the plates and decreasing distance between them, the capacitance of capacitor

7. If we double the separation between two charges then coulomb’s force will become

8. The power of an electric bulb is 100W, it is connected to 110V power supply. The resistance of electric bulb will be

9. Terminal voltage “V1” of the battery is greater than emf of the battery when:

10. The temperature coefficient of semi conductor is negative because