Physics Past Questions and Answers

An object placed on the principle axis of a convex lens of focal length 10m produces a real image of double magnification. The image distance from the lens is

A 30cm
B 25cm
C 20cm
D 15cm
E 10cm

Question 37:

A liquid-in-glass thermometer should quickly register temperature changes. This is achieved by choosing a liquid that

A Is opaque
B Has high density
C Has regular expansion
D Has a high thermal conductivity
E Can wet glass

Question 38:

The extension in a spring when 5g wt was hung from it was 0.56cm. If Hooke's law is obeyed, What is the extension caused by a load of 20g wt?

A 1.12m
B 2.14cm
C 2.52cm
D 2.80cm
E 2.24cm

Question 39:

Which of the following is NOT directly associated with direct current (DC)?

A A dry cell
B A moving coil galvanometer
C A transformer
D A lead- acid accumulator
E A commutator

Question 40:

The relationship between the period T and the length T of a smile pendulum is T = 2\( \pi \) \( ( \frac{I}{g}) ^{ \frac{1}{2} } \). From experiment data of T and I, one can obtain the following graphs, i. T vs.I ii. T vs I² iii. T² vs. I iv. T vs \( \sqrt{I} \) v. logT vs logI. Which of the following graphs, are linear?

A All
B Only i and ii
C Only iii and iv
D Iii,iv and v
E None of them