Physics Past Questions And Answers
A thermocouple thermometer is connected to a millivoltmeter which can read up to 10mV. When one junction is in ice at 0°C and the other is steam at 100°C, the millivoltmeter reads 4mV. What is the maximum temperature which this arrangement can measure
- A. 100oC
- B. 248oC
- C. 250oC
- D. 350sup>oC
A parallel beam of light is to be obtained from the headlamp ofa car. At which of the following positions should the source of light be placed from the pole of its spherical minor?
- A. At the focal point
- B. At the centre of curvature
- C. Beyond the centre of curvature
- D. Between the focal point and the pole
Which of the following statements is correct?
- A. the density of a liquid decreases when it expands
- B. the density of a liquid increases when the liquids are heated
- C. the real expansivity of a liquid is less than its apparent expansivity
- D. a liquid changes to solid when heated to a sufficiently high temperature
At constant pressure, the density of a fixed mass of gas is
- A. constant with temperature
- B. proportional to its volume
- C. inversely proportional to its temperature
- D. independent of its volume
Which of the following properties make the convex mirror useful as a driving mirror? i. the image is real. ii. the image is erect. iii. it has a wide field of view. iv. the image is magnified.
- A. i, ii, and iv
- B. i, ii, iii
- C. ii and iii
- D. i and iii
.An inductor of inductance 10 H is connected across an a.c circuit source of 50 V, 100 Hz. What is the current in the circuit? [π = 3.14]
- A. 0.200A
- B. 0.070A
- C. 0.050A
- D. 0.008A
Consider the three forces acting at O and in equilibrium as shown in the figure. Which of the following equations is/are CORRECT?
I. P1 cos θ1 = p1 cos θ2
II. P3 = P1 cos θ4 + P2cos2
III. P1sinθ1=P2sinθ2
- A. I only
- B. II only
- C. III only
- D. I, II and III only
Which of the following is not a part of the electro-magnetic spectrum?
- A. x-rays
- B. microwaves
- C. infrared radiation
- D. alpha rays
Which of the following is a vector?
- A. Electric charge
- B. Electric field
- C. Electrical potential difference
- D. Electrical capacitance
Calculate he wavelength of a note which is one octave lower than a note of 256Hz in a medium in which the speed of sound is 352ms-1
- A. 0.69m
- B. 1.38m
- C. 2.75m
- D. 5.50m