## Search found 38 matches

Fri Feb 01, 2019 8:55 pm
Forum: Physics
Topic: BdPhO Regional (Dhaka-South) Secondary 2019/3
Replies: 1
Views: 686

### Re: BdPhO Regional (Dhaka-South) Secondary 2019/3

We know, $T=2\pi\sqrt{\dfrac{m}{k}}$
So, $T_n=2\pi\sqrt{\dfrac{2m}{4k}}=\dfrac{1}{\sqrt2}2\pi\sqrt{\dfrac{m}{k}}$
$\therefore \dfrac{f_n}{f}=\dfrac{T}{T_n}=$$\sqrt2$
Fri Feb 01, 2019 6:52 pm
Forum: Physics
Topic: BdPhO Regional (Dhaka-South) Secondary 2019/2
Replies: 1
Views: 748

### Re: BdPhO Regional (Dhaka-South) Secondary 2019/2

Here, time $=(50-30) s = 20 s$
So, Heat $=(50*20) = 1000 J$
So, the specific latent heat of the fusion $= \dfrac{1000}{4}=\boxed {250}$ $Jkg^{-1}$
Tue Jan 29, 2019 4:35 pm
Forum: Physics
Topic: BdPhO Regional (Dhaka-South) : Problemsets
Replies: 0
Views: 1370

### BdPhO Regional (Dhaka-South) : Problemsets

$***BdPhO$ $Regional$ $(Dhaka-South)$ $:$ $Secondary***$ $Problem-1$ What will be the reading on the voltmeter? (See the figure) $Problem-2$ A solid object of mass $4 kg$ is heated at a constant rate $50 W$. The object is kept inside a thermally isolated container so that it cannot radiate heat to ...
Tue Jan 29, 2019 9:26 am
Forum: Secondary Level
Topic: BDMO PREPARATION : Higher Math Problem (Binomial Expansion)
Replies: 1
Views: 2497

### BDMO PREPARATION : Higher Math Problem (Binomial Expansion)

Which is greater $99^{50}+100^{50}$ or, $101^{50}?$
Mon Jan 28, 2019 10:07 pm
Forum: Physics
Topic: BdPhO Regional (Dhaka-South) Secondary 2019/8
Replies: 0
Views: 1504

### BdPhO Regional (Dhaka-South) Secondary 2019/8

BdPhO Regional (Dhaka-South) Secondary 2019(8).png Consider two spheres with charge density $+ρ$ and $-ρ$ respectively. The radius of both the spheres is $R$. The centers of the two spheres are at distance $d$ from each other (Here $d<2R$). There is no charge in the intersecting region. Consider a ...
Mon Jan 28, 2019 9:53 pm
Forum: Physics
Topic: BdPhO Regional (Dhaka-South) Secondary 2019/7
Replies: 1
Views: 8312

### BdPhO Regional (Dhaka-South) Secondary 2019/7

BdPhO Regional (Dhaka-South) Secondary 2019(7).png Adventurous Azmain slides down a water slide. He starts with zero initial velocity. The initial point $A$ is at a height $H$ from the ground and the other end $B$ is at a height $h$. The tangent line to the water slide at the point $B$ makes an ang...
Mon Jan 28, 2019 9:17 pm
Forum: Physics
Topic: BdPhO Regional (Dhaka-South) Secondary 2019/6
Replies: 1
Views: 8316

### BdPhO Regional (Dhaka-South) Secondary 2019/6

BdPhO Regional (Dhaka-South) Secondary 2019(6).png A light ray is incident on a rectangular slab $ABCD$ at an angle $θ$ with the normal. The refractive index varies with vertical distance $y$ in the rectangular slab. Refractive index, $n(y) = ky$, for $0 < y < h$, where $k$ is a constant. At what a...
Mon Jan 28, 2019 4:28 pm
Forum: Physics
Topic: BdPhO Regional (Dhaka-South) Secondary 2019/5
Replies: 0
Views: 1478

### BdPhO Regional (Dhaka-South) Secondary 2019/5

A boy is holding a ball in his hand in a train moving with constant velocity $v$. Then he releases the ball from height $H$ above the floor of the train. What trajectory will the boy see? If the train moved in a constant acceleration, $a$ what would be the trajectory with respect to the boy? How far...
Mon Jan 28, 2019 4:16 pm
Forum: Physics
Topic: BdPhO Regional (Dhaka-South) Secondary 2019/4
Replies: 1
Views: 8226

### BdPhO Regional (Dhaka-South) Secondary 2019/4

Consider an isolated system consisted of a ball, and a bucket of water. The ball is released from height, $H$ above a bucket of water. The initial temperature of the water-bucket system and the ball are $T_1$ and $T_2$ respectively. What will be the final temperature of the water after the ball is d...
Mon Jan 28, 2019 4:11 pm
Forum: Test Forum
Topic: বাংলায় লেখা
Replies: 0
Views: 8405

### বাংলায় লেখা

আমি বর্তমানে ১০ম শ্রেণিতে অধ্যয়নরত।