An object is placed in front of a converging lens of a fo...
An object is placed in front of a converging lens of a focal length 20cm. The image is virtual and has a magnification of 2. What is the distance of the object from the lens?
5cm
10cm
30cm
40cm
Correct answer is B
V = -2u
F = \(\frac{uv}{u + v}\)
20 = \(\frac{uv - 2u}{u - 2u}\)
u = 10cm
I. Low pressure. II. High pressure. III. High p.d. IV. Low p.d. Which combination of the above i...
Which of the following factors does not increase the rate of evaporation of water in a lake? ...
In a series R - C circuit, the resistance of the resistor is 4 Ω and capacitive reactance is 3...
Presbyopia is a defect of the eye resulting from ...
An ammeter connected to an a.c circuit records 5.5. The peak current in the circuit is ...
Local action is normally prevented from taking place in a simple electric cell by ...