## St. Xavier BASED PRACTICE MODEL QUESTION

### Physics

- The energy of charged capacitor increases by 21 % when additional charge 2C is added to its plate. The charge on the capacitor previously is:
- 10 C
- 15 C
- 20 C
- 25 C

- The power of a lamp is 40W at certain ac voltage. If the supply voltage is halved, the power would be
- 40 W
- 20 W
- 10 W
- 80 W

- A small circular flexible loop of wire of radius r carries a current I. It is placed in a uniform magnetic field B. The tension in the loop will be doubled if :
- I is doubled
- B is halved
- r is doubled
- both B and I are doubled

- A voltmeter has resistance of 2000𝞨 and it can measure upto 2V. If we want to increase its range by 8V, then required resistance in series will be
- 4000𝞨
- 6000𝞨
- 7000𝞨
- 8000𝞨

- The resistance of discharge tube is
- zero
- ohmic
- non – ohmic
- depends upon pressure

- Which of the following transitions in a hydrogen spectrum emits photons of the highest frequency
- n = 1 to n = 2
- n = 2 to n = 1
- n = 2 to n = 2
- n = 6 to n = 2

- Hydrogen atom does not produce x-rays because
- its energy levels are too close to each other
- its energy levels are too far apart
- it is too small in size
- it has a single electron

- If the forward voltage in a semiconductor diode is doubled, the width of depletion layer:
- increases
- decreases
- remains unchanged
- becomes zero

- For full wave rectification, the minimum number of diodes used is
- 1
- 2
- 3
- 4

- Two photons approach each other. Their relative velocity will be
- 2c
- c
- c /2
- zero

- When the length of a compound microscope tube increases, its magnifying power :
- decreases
- Increases
- does not change
- may increase or decreases

- Neutral temperature of a thermocouple is 320°C. The cold junction is at 10°C. The inversion temperature is :
- 320°C
- 630°C
- 640°C
- 650°C

- The maximum horizontal range of a projection is 400 m. The maximum height attained by it will be:
- 100 m
- 200 m
- 400 m
- 800 m

- If the momentum of a body is doubled, the kinetic energy is:
- halved
- unchanged
- doubled
- increase 4 times

- The dimensional formula of angular momentum is:
- [ML
^{2}T^{-2}] - [ML
^{-2}T^{-2}] - [ML
^{2}T^{-1}] - [ML
^{-2}T^{1}]

- [ML